Leslie is widely expected run for the Liberal nomination in the Ottawa-Orléans riding, and an on-the-ground organization for his likely election campaign is already underway.
For the Liberals he was a highly desired catch, a veteran of Cyprus and Croatia, when it was part of the former Yugoslavia, as well as Afghanistan. His pedigree is star-studded with former Liberal defence ministers. Both grandfathers served in the posts, a position Leslie is probably slated for if he becomes an MP and the Liberals form a government.
He presents an intriguing parallel to Liberal Leader Justin Trudeau in the sense of trying to fulfil what might be perceived as destiny because of a father or grandfather.
The lead-up to his Montreal showcasing was marred when news broke last week that he had charged $72,000 in moving expenses for relocating from one Ottawa house to another a few kilometres away. Most of the bill was probably for real estate fees attached to the hefty prices that houses in Ottawa's toney Rockcliffe Park tend to fetch.
Leslie has pointed out that he followed the moving expense rules that apply to anyone in the military entitled to one last paid move at retirement.
As a former soldier, it's a response that most would judge as reasonable, but as an aspiring politician in the context of disgraced senators who have also said they were following rules, more questions have arisen about his political judgment during a particularly sensitive atmosphere about taxpayer-funded expenses.
Liberals have been quick to label the Conservative attack on his expenses, especially a comment from Defence Minister Rob Nicholson that the moving fees were "grossly excessive," as a smear tactic by the government.
Liberal sources say that in his speech today, Leslie will sound more like "a general," and media reports say that he will reveal the Tories tried to recruit him as a candidate before he became an adviser to Trudeau. If that is true, it's likely the Conservatives would have caught the moving fee in their vetting process, and were perhaps not bothered by it.
It's said Leslie's family will be in the audience, including his daughter who served in Afghanistan.
After his speech, Leslie is to hold a scrum with reporters for the first time since his moving expenses were revealed.