Maxime Bernier's campaign says it will now forward any complaints about membership violations to the Conservative Party and no longer publicly discuss them, including allegations of vote-buying against fellow leadership candidate Kevin O'Leary.
Kory Teneycke, the former vice-president of Sun News and communications director to Stephen Harper who is advising Mr. Bernier on his leadership bid, said the campaign will not get into a "tit-for-tat" for the remainder of the race.
"We will be forwarding any complaints or concerns or rumours or allegations to the party when we receive them, but we will not be giving comment to the media on any specifics pertaining to those," Mr. Teneycke told The Globe and Mail.
"We have confidence in the party's membership review process and the rules process and the ability of the party to police this."
When asked if the campaign has sent information to the party about the recent allegations against Mr. O'Leary, Mr. Teneycke would not answer.
"We're not going to get into an ongoing dialogue on this issue or other rules issues with the media," he said. "We're going to send it to the party and you're not going to know about it."
The move from Mr. Bernier's team was made after the O'Leary camp accused their Quebec rivals of mass membership fraud last week.
People who want to vote in a leadership contest must buy a party membership, and campaign organizers try to sell as many as possible in the hope the new members will support their candidates. Irregularities in the process have frequently been a source of friction.
On Sunday, Mr. Bernier's campaign provided The Globe with a sworn affidavit alleging one of Mr. O'Leary's organizers in the Sikh-Canadian community in Brampton, Ont., offered to pay for memberships for other people – a clear breach of party rules.
The Globe and Mail published a story about the allegations, but Conservative Party spokesman Cory Hann said on Tuesday the party received no information from Mr. Bernier's campaign and would not pursue an investigation without it.
Mr. Bernier's communications director, Maxime Hupé, then told The Globe the campaign considered the matter closed and "we won't push that further."
Mr. Hann sent a statement to The Globe on Tuesday saying the party has examined and will continue to look at any information that helps maintain the integrity of the leadership race.
"This will be a fair contest, and we'll take all necessary steps to ensure that," Mr. Hann wrote. "Members can be confident our leadership race has been, and will remain fair, and all measures are being taken to ensure that."
The fracas between the two perceived front-runners in the 14-person race comes a week before membership sales close on March 28. The party will elect its new leader on May 27.
Ari Laskin, Mr. O'Leary's spokesman, said the campaign has not seen any documentation on Mr. Bernier's accusations. "Mr. O'Leary is continuing to call for the Party to do a full audit of the membership list once the list is finalized on the 28th," Mr. Laskin said in an e-mail.
Six Sikh-Canadians swore an affidavit alleging that Ron Chatha, president of the Conservative Brampton East Riding Association and an organizer for Mr. O'Leary, offered to pay for their memberships.
Mr. Chatha denied it, saying he was the first to complain to party headquarters about false memberships.
A party official confirmed Mr. Chatha had flagged suspicious memberships that led to an investigation and the removal of more than 1,300 people from the party rolls on Friday.
Last Thursday, Mr. O'Leary's team said it had discovered a large number of people in the Tamil-Canadian community in Toronto were signed up without their knowledge using untraceable prepaid credit cards. Sources said the move allegedly involved a Tamil-Canadian connected to the Bernier campaign.
Mr. Bernier denied his campaign was buying votes and called Mr. O'Leary a "loser."
The Conservative Party investigated the complaint and found memberships were bought through two IP addresses for 1,351 people who did not pay themselves as required under the rules. Those memberships were cancelled.
With a report from Robert Fife