Liberal Leader Justin Trudeau has condemned the Conservatives for what he called "a pure partisan attack" against retired lieutenant-general Andrew Leslie​, who served in the Canadian Forces for 35 years before retiring in 2011.

It was the first time Trudeau publicly defended Leslie, a senior adviser for the Liberal Party, since the Conservatives accused him of "grossly excessive" moving expenses.

"It's quite clear that this government is ready to be vicious and ruthless with anyone, even with a Canadian hero, that dares disagree with their ideology and their approach," Trudeau told reporters in Quebec City on Tuesday.

Leslie, who agreed last September to advise Trudeau on foreign and defence issues, is said to be touted as a Liberal candidate in the next federal election.​

The Conservatives, over the weekend, criticized Leslie for what they called inappropriate moving expenses of $72,000.

Leslie fired back saying he's been shot at by "real bullets" and can withstand the scrutiny that comes with working for Trudeau.

The retired lieutenant-general said he simply accepted a standard benefit available to any veteran with 20 or more years of service that allows veterans a final move to anywhere in Canada.

Leslie said he and his family decided to move from their home in Ottawa to a smaller one nearby. 

'Big mistake'

The attack against Leslie came a week before he is to address the Liberal faithful during a convention in Montreal next weekend.

'This is yet another example of how out of touch, tired, and irresponsible this government is.' —Justin Trudeau, Liberal leader

Trudeau deplored the attack against Leslie, calling it a "big mistake" on the part of a government whose policies have clashed with the needs of its veterans.

"I think they've made a big mistake in being very much offside with how Canadians feel about our veterans."

"This government focuses on one thing and one thing only: the interests of the Conservative Party of Canada and not the well-being of veterans or the well-being of Canadians," he said.

"This is yet another example of how out of touch, tired, and irresponsible this government is," the Liberal leader said.

Trudeau said he spoke with Leslie and was assured he had followed all the rules.

National Defence Minister Rob Nicholson said he has instructed his department to undertake a review of the benefit program.

"The policy was never intended to have taxpayers pay over $70,000 for Andrew Leslie or other generals to change houses within the same neighbourhood," a spokesperson for the minister told CBC News on Tuesday.

Leslie oversaw the 2011 report on transformation for the Department of National Defence.

Senators not welcomed?

Leslie, who is scheduled to speak during the Liberal Party convention in Montreal this week, was to be introduced by another high-profile retired general.

Romeo Dallaire 0131212

Senator Roméo Dallaire was scheduled to introduce Leslie at the upcoming Liberal Party convention in Montreal this week. (Patrick Doyle/Canadian Press)

CBC News Network's Power and Politics has learned that Senator Roméo Dallaire will no longer be introducing Leslie during the keynote address.

One source told host Evan Solomon that after Trudeau expelled all Liberal senators out of his caucus, Dallaire no longer felt welcome to deliver the introductory remarks.

Another source told Solomon the party did not want to have a senator introduce Leslie and Dallaire felt unwelcome, so the decision was mutual.

It is not clear how many senators will be in attendance at this week's Liberal convention in Montreal.

With files from The Canadian Press