The Senate has narrowly defeated a motion to divide the Liberal government's budget bill, following a personal appeal from Finance Minister Bill Morneau.
In a late-night 38-38 vote with one abstention, senators defeated a motion to split Bill C-44 in a way that removes the proposed Canada Infrastructure Bank Act from the main budget bill.
The speaker reminded senators shortly after the 10 p.m. vote that a tie means the motion is defeated.
The motion was put forward last week by independent Senator André Pratte, who said it would give senators more time to thoroughly study the proposed $35-billion infrastructure bank.
Mr. Morneau spent nearly two hours last week as a witness before the Senate national finance committee, where he urged Mr. Pratte and other senators to approve the budget bill intact before Parliament rises for the summer recess.
The motion to split the budget bill has triggered considerable debate both within the Senate and among the broader public over the appropriate role of the unelected Senate.
Mr. Pratte promoted his motion as a vehicle for the Senate to draw a line in the sand against the use of wide-ranging omnibus bills that make it more difficult for Parliament to thoroughly study all of the bill's component parts.
The proposed infrastructure bank is aimed at attracting private capital from large institutional investors, such as pension funds, to invest in Canadian infrastructure projects.
Prime Minister Justin Trudeau has followed through on a campaign pledge to appoint senators who sit as independents, breaking with the tradition set by previous prime ministers who tended to fill vacancies with loyalists of the governing party.
The large number of independents has led to a more unpredictable Senate.
Critics of Mr. Trudeau's approach have argued that his appointments are sympathetic to Liberal policies even though they are not partisan Liberals.
An analysis of voting records released this week by CBC News found Mr. Trudeau's independent appointments have voted with the government 94.5 per cent of the time.
On Thursday, the Senate Speaker sided with the government representative in the Senate by issuing a ruling that found Mr. Pratte's motion was not in order procedurally.
The Senate voted to overrule that decision, which allowed the motion to proceed.
The motion was designed to instruct the Senate national finance committee to split the bill as part of its review of the legislation.
It is still possible the committee may consider other amendments.
The House of Commons is scheduled to break for the summer on Friday.
When the Senate amends legislation, it must be returned to the House of Commons for approval.
It is not clear, however, whether the Senate will complete its work on the budget bill before Friday, when the House is scheduled to rise.
A spokesperson for Government House Leader Bardish Chagger declined to say on Monday afternoon, ahead of the Senate's vote, whether the Liberal government was considering having MPs sit longer in order to pass the budget bill.