The temptation is to compare Justin Trudeau’s Prime Minister’s Office with that of Stephen Harper. But the more interesting comparison is with the PMO of his father.

It was Pierre Trudeau who gave us the modern version of the PMO. Before he inherited power from Lester Pearson in 1968, the office consisted of about 40 staff members; the more influential among them were senior advisers without clear responsibilities. The elder Mr. Trudeau recoiled from what he considered a chaotic work environment, in which ministers made ad hoc decisions with little central oversight, and the prime minister himself often set policy on the fly. So he set about instilling structure – more than doubling the PMO’s size, and putting in place powerful officials with clear lines of responsibility they were not to cross.

The degree of regimentation in the offices of the prime ministers between the two Trudeaus has varied, and sometimes the dynamics have shifted even within a single mandate. Mr. Harper, for instance, had a more hierarchical office when Nigel Wright was his chief of staff, and a somewhat more fluid one at other times. But few of them can be accused of actively seeking out a casual and free-flowing backroom dynamic.

So it has been striking to hear some government insiders use the word “Pearsonian” to describe what Justin Trudeau is aiming for in his PMO.

That’s not to say he is about to turn the clock back to the 1960s, exactly. In fact, he is as much trying to stay in touch with the more fluid management practices of the Google era – something he also embraced during a pre-election rebuild and modernization of the Liberal Party that some insiders compared to launching a start-up.

In any event, he is pushing, harder than just about any prime minister since his father, for a less centralized and regimented, more open and collaborative decision-making process than Ottawa has been conditioned to expect. If it works, it will produce more innovative and well-considered policies than would otherwise be possible; if it fails, a lack of discipline could make things messy in a hurry.

With the PMO having reached roughly 100 members by the time he took over from Mr. Harper, it appears Mr. Trudeau will attempt to shrink it again – although by how much won’t be clear until hiring has been completed, early this year. More ambitious and fraught is an attempt at a mostly “flat,” non-hierarchical organizational structure for upper-level staff, facilitating the looser, more free-flowing working culture.

Much has been made – with plenty of cocked eyebrows – about Mr. Trudeau’s pledge to re-empower cabinet, giving ministers greater control over what they say in public and how they steer their files in private than was the case under Mr. Harper in particular.

Less noticed has been the attempt at fluidity within the PMO itself.

There are still a couple of staffers at the top of the food chain, but even their roles are not that clear-cut. A common assumption in Ottawa is that principal secretary Gerald Butts is in charge of policy and communications strategy, while chief of staff Katie Telford runs operations (i.e. makes sure things actually get done). That’s true, up to a point. But there are few boundaries to delineate their roles. No significant decisions – about policy implementation or responses to emerging issues, or the contents of Mr. Trudeau’s speeches – are made without both weighing in.

Nor, it appears, are they usually made without quite a few other people weighing in as well. Mr. Trudeau is known to favour big, collaborative discussions that include other staffers, speaking as freely as Ms. Telford and Mr. Butts, encouraged to challenge their bosses and each other. There has been little ranking of those staffers within the PMO, and they are not limited to participating only in discussions that fall directly within their mandates. With an aim to create a less formal atmosphere, work spaces have been loosened up with more couches and other furniture supposed to encourage relatively relaxed conversations, between staffers and, in some cases, involving the PM himself.

Among the reasons many leaders avoid hearing from lots of internal voices on every issue is the potential for paralysis. Paul Martin, who tried during his brief time as prime minister to have a large group of staffers argue out decisions in front of him, was so notorious for being unable to sort through all the advice that The Economist branded him Mr. Dithers. U.S. President Barack Obama, particularly in his first term, was frequently accused of wasting time and political capital trying to litigate every issue behind the scenes.

Mr. Trudeau, who, in contrast to his much chillier father, is as affable and eager to please a prime minister as this country has seen, could well be susceptible to such pitfalls. Cynics suggest he will ultimately just turn to Mr. Butts for a final call. Among insiders, the more common response – beyond Mr. Trudeau being capable of running a solid meeting, separating good advice from bad, then making a decision and sticking with it – boils down to his staff having great chemistry and being less prone to competition than most. (Or, as one senior Liberal put it, “We have a strict ‘no asshole’ rule.”)

For now, the fairest criticism of Mr. Trudeau’s PMO may be that, for all its fluidity and camaraderie, too many senior staffers come from the same small world. Considerably less diverse than Mr. Trudeau’s cabinet, they are disproportionately from Ontario, with nearly half the upper ranks – including Ms. Telford and Mr. Butts – having cut their teeth at Queen’s Park. Most played significant roles on his campaign. Although they may offer different takes on individual issues, there are few indications yet that many of them have dramatically different worldviews; moderately left-of-centre pragmatic activism seems to rule.

As some of this crowd exits and replacements step in, as is likely to happen even before Mr. Trudeau has finished serving a single term, the turf protection and regimentation that came to plague the offices of his predecessors may return.

But for now, with the upper ranks of this new PMO set, there are a dozen key people helping Mr. Trudeau chart the course of his new government.

Adam Radwanski writes on national politics for The Globe and Mail.

Katie Telford

Chief of Staff

Outsiders tend to assume Mr. Butts sets the strategy and Ms. Telford implements it, but it’s not that simple. While definitely more focused on organizational matters than her “co-CEO,” she also has strong influence on policy and communications discussions. As Mr. Trudeau’s national campaign director, Ms. Telford developed a reputation for favouring data- and results-driven decision-making – a counterbalance to Mr. Butts’s read on Mr. Trudeau’s emotional connections with Canadians. She appears inclined toward a strong degree of delegation, but often to people in whom she has developed a large amount of trust through previous working relationships – reflected in some of the PMO’s other staffing decisions.

Jane Taber reports on Ottawa’s newest major powerbroker PMO’s Katie Telford: ‘People underestimate her, and that has worked to her advantage’

Gerald Butts

Principal Secretary

With by far the highest public profile of any political staffer in Ottawa, Mr. Butts – a top adviser to former Ontario premier Dalton McGuinty and a close friend of Mr. Trudeau since their McGill days – is commonly assumed to run the government behind the scenes. That’s an exaggeration: He and Ms. Telford are on equal footing and, in some instances, his is just one of several voices, with Mr. Trudeau rejecting his advice when he does not agree with it. Still, nobody other than the Prime Minister himself has had a stronger hand in shaping Mr. Trudeau’s political identity and agenda. Fiercely protective of Mr. Trudeau, and at times combative with journalists and critics, he is both a public and an internal guardian of the government’s narrative.

Jeremy Broadhurst

Deputy Chief of Staff

A veteran political staffer who was chief of staff during Bob Rae’s stint as the Liberals’ interim leader, Mr. Broadhurst essentially served as Ms. Telford’s second-in-command during the party’s organizational rebuild leading up to last year’s election, and during the campaign itself. Known as a workhorse, he is reprising something akin to that role in government, including dealing with some of the more nitty-gritty aspects of operational matters. While usually on the same footing as the other senior officials below Ms. Telford and Mr. Butts, he would likely be the person to step in if, for some reason, both were unavailable.

Cyrus Reporter

Senior Adviser

After serving as Mr. Trudeau’s chief of staff during his time as third-party leader, Mr. Reporter has now moved into a sort of project-management and trouble-shooting role in which he takes on one major and politically fraught file at a time, helping to co-ordinate government departments. To date, his job has mostly involved serving as the PMO’s point man on the Syrian-refugee file. A long-time chief of staff to Allan Rock when Mr. Rock was in Jean Chrétien’s cabinet, the British Columbia native has more experience working in federal government than anyone else in the PMO’s upper ranks.

Mathieu Bouchard

Senior Adviser

It has not escaped the francophone media that the PMO is decidedly light on senior staff from Quebec; Mr. Bouchard’s primary responsibility is to make sure the province’s perspective and interests are well represented. Relatively new to federal politics, the erstwhile partner at Montreal law firm Irving Mitchell Kalichman was brought into the fold by friend and former colleague (and now Heritage Minister) Mélanie Joly – assisting with Mr. Trudeau’s debate preparations, among other things, during the campaign. As well as stickhandling Quebec relations, Mr. Bouchard is also the PMO’s lead on legal affairs: roles that will soon converge as the government responds to Quebec’s legalization of medically assisted suicide.

Trudeau adviser Mathieu Bouchard more than just PMO’s ‘Quebec guy’

Roland Paris

Senior Adviser

The lead on foreign policy, Mr. Paris is the only senior staffer to come from the academic world – although he does have experience as a bureaucrat in the Foreign Affairs ministry and the Privy Council Office, where he served during the final years of the last Liberal regime. Subsequently, as the founding director of the University of Ottawa’s Centre for International Policy Studies, he penned an open letter last spring to whoever would be the next prime minister. It included calls for increased involvement in United Nations peace operations and other multilateral efforts; a “comprehensive response to fragile states” in the Middle East and elsewhere, with a focus on economic, social and security-related causes of instability; and a greater emphasis on trade with China.

Kate Purchase

Director of Communications

While some people in her role delegate most media relations to the press secretaries under them, Ms. Purchase – herself a former press secretary who also served as the Liberals’ communications director during the election campaign – has so far been very hands-on in trying to establish cordial relations with journalists. With time, she will likely settle into managing the sizable PMO wing under her watch, while mapping an agenda for policy roll-outs and announcements. As with past communications directors, she will be involved in as many discussions as anyone, save for the chief of staff or principal secretary, and benefits from having a well-established working relationship with both of them.

Michael McNair

Director of Policy

An investment banker who studied at the London School of Economics, Mr. McNair worked as a policy adviser for Stéphane Dion and Michael Ignatieff; he began advising Mr. Trudeau well before the federal election. The big challenge for Mr. McNair and his staff is translating the platform he helped to write into implementable policy. He and Ms. Purchase, who have worked together since the Liberals’ darkest days under Mr. Ignatieff, have a level of mutual comfort that should help them navigate some of the typical tensions between policy aspirations and public buy-in. There is some history of policy directors being marginalized by other staff – a potential concern for Mr. McNair, given Mr. Butts’s strong involvement in most policy files, and an interesting test of how collaborative the office proves to be.

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Zita Astravas

Director of Issues Management

While she played a major role in Kathleen Wynne’s office, serving as the Ontario Premier’s top spokesperson, Ms. Astravas has nevertheless made a significant leap. Her job is one of the most stressful in Ottawa, because it often involves putting out fires – or, ideally, trying to prevent them – by making sure the government is not caught off guard by the daily news cycle. Ms. Astravas will have more contact with ministers’ offices than most other PMO staffers, although, with Parliament having sat for only a few days under this government, the routine for that interaction has yet to be set.

John Zerucelli

Director of Operations

A young Chrétien staffer who went on to practise law and who recently served as chief of staff to Deb Matthews, president of the Ontario Treasury Board (considered the most powerful minister in Kathleen Wynne’s cabinet), Mr. Zerucelli is known for being the best in the business at running leaders’ tours, including Mr. Trudeau’s in the recent campaign. He will continue to manage the logistics for the Prime Minister’s public appearances, and also will oversee the regional desks that are supposed to monitor and manage the PM’s relations with different parts of the country. This could take on particular importance, given the Ontario-centrism of the PMO’s upper ranks.

Dan Arnold

Director of Research and Advertising

A transplanted Albertan (he blogs as “Calgary Grit”), Mr. Arnold was lauded by other campaign officials for using advanced polling methods that helped the Liberals tap into, or even predict, on-the-ground trends across the country. His job now is to keep tabs on public opinion from inside government, and try to anticipate how prospective policies are likely to play. While it’s fair to ask whether the Liberal Party, rather than the public, should not be paying for this, the job has existed under previous governments. Where Mr. Arnold may break some new ground is with advertising, where he has to help Mr. Trudeau keep his promise to end partisan ads that are financed by the government.

Mary Ng

Director of Appointments

Another alumna of the Ontario Legislature, and a close friend of Ms. Telford dating back to their time in then-education minister Gerard Kennedy’s office, Ms. Ng must have an unenviable inbox these days: She is charged with helping to figure out who gets what job in the new government. It will be frenetic work in the short term. But even thereafter, there will be enough (at least theoretically) non-partisan appointments – to everything from Crown corporations to judgeships – to keep her busy. It seems she has a seat at the table for key meetings, important given that nobody should have a better knowledge of key personnel and their capabilities.