Former Tory MP, Michael Ma, is welcomed to the Liberal Party by Mark Carney.

So the Groucho Marx Party – “these are my principles: if you don’t like them, I have others” – has another member.

Michael Ma, who was elected as Conservative MP for Markham-Unionville about five minutes ago, has flipped to the Liberals, taking their standings to one tantalizing seat short of a majority that would keep them in power until 2029. You can hardly blame Mark Carney from encouraging bad behaviour in the circumstances.

But MPs have a responsibility to their constituents.

There will, no doubt, be other unscrupulous Conservatives lining up to get the Liberals over the majority line, like Augustus Gloop diving into Willy Wonka’s chocolate river. To be fair, the lure of personal aggrandizement is matched for some by the push factor of a Conservative Party leadership that appears to relish upsetting the median voter.

However, would-be floor crossers should think twice if they want to qualify for their six years of pensionable service. It rarely ends well. Parliament nerds will no doubt prove me wrong but from memory only a handful of MPs have moved from one party in the House of Commons to another and subsequently been re-elected in the past two decades or so.

Keith Martin left the Canadian Alliance to protest the merger with the Conservatives in 2004, sat as an independent and subsequently won his Vancouver Island riding as a Liberal; Progressive Conservative Scott Brison made a similar journey and won six elections as a Liberal MP; Conservative Belinda Stronach helped Paul Martin stave off a potentially disastrous election in 2005 by joining the Liberals in dramatic fashion and she was re-elected in Newmarket-Aurora in 2006, before losing in 2008; Leona Alleslev won her suburban Toronto riding for the Liberals in 2015 and then for the Conservatives in 2019, before losing to her former party in 2021; while, Jenica Atwin won her Fredericton riding for the Greens in 2019 and for the Liberals in 2021.

The more typical stories are of mediocrities who think they are Socrates fooling themselves that their personal brand will carry them to victory under a different banner.

One such cautionary tale is that of Eve Adams, who won the Mississauga-Brampton South riding for the Conservatives in 2011, beating Navdeep Bains, before crossing to the Liberals before the 2015 election. She later lost the Liberal nomination for the Eglinton-Lawrence seat to future minister, Marco Mendicino, and subsequently failed in her bid for a seat on Hamilton City Council.

The reason that crossing the floor is a career-limiting move is that it connotes a lack of principle. Voters, fools that they are, genuinely value honesty, character, integrity and loyalty. The floor crosser, rightly or wrongly, is seen as having abandoned party esprit de corps for personal advancement.

As David Lloyd George once famously said of serial floor-crosser, former British foreign secretary Sir John Simon: “The right honourable and learned gentleman has twice crossed the floor of this House, each time leaving behind a trail of slime”.

Conversely, the man or woman of principle is prepared to head into the political wilderness if he or she cannot stomach the direction in which their party is heading.

In the course of researching my upcoming book on Irwin Cotler, one of his staff members told me that the Conservatives tried to lure the former justice minister to join them, after failing to unseat him in 2011. I raised it with him and he conceded that the Harper government had extended that option, “including offering me a ministry if I would do so. But it was never an option for me and I made that very clear to them,” he said.

I don’t think I have met anyone in a journalistic career spanning more than three decades who lives their virtue like Cotler, as opposed to merely signalling it.

He summed up an approach that should be standard for all members of Parliament. “For me, it was an issue of principle. I would never cross the floor. My mandate came from my constituents – for me personally but also for the party I was representing. If I felt I could no longer be a member of that party, then my option and responsibility was to resign.”

MPs are billed as “Honourable Members” in Hansard, the official report of all debates. They should live up to that characterization.