OTTAWA -- Jane Philpott departed a meeting of her fellow Ontario Liberal MPs after just a few minutes Tuesday, leaving them to debate the question of whether she should remain a member of caucus.

The largest provincial group of Liberals gathered on Parliament Hill one day before a national meeting in which Liberal legislators could vote to expel both the former Indigenous services minister and ex-attorney general Jody Wilson-Raybould.

Toronto MP John McKay said he sees no way for either Wilson-Raybould or Philpott to stay in the Liberal caucus -- he's dismayed by Wilson-Raybould's behaviour and believes she and Philpott are "joined at the hip," he said.

The two quit Prime Minister Justin Trudeau's cabinet over his handling of the SNC-Lavalin affair, in which Wilson-Raybould says she was relentlessly pressured by Trudeau and others to avert a criminal prosecution of the Montreal engineering firm.

Several Ontario MPs say Wilson-Raybould has sent her fellow caucus members a two-page letter making her case for remaining as a Liberal MP.

McKay said he was unmoved by the letter's contents. Toronto Liberal Judy Sgro agreed the letter is "too little, too late" and said she sees little difference between Wilson-Raybould and Philpott.

Earlier Tuesday, members of the Trudeau cabinet focused on what was behind Wilson-Raybould's decision to surreptitiously record a phone conversation with the country's top public servant.

Infrastructure Minister Francois-Philippe Champagne criticized Wilson-Raybould's ethics, saying he had never recorded any conversations he had while working as a lawyer.

Tourism Minister Melanie Joly said what Wilson-Raybould did in secretly recording her Dec. 19 phone conversation with Privy Council clerk Michael Wernick was "fundamentally wrong."

Wilson-Raybould provided a 17-minute audio recording to the House of Commons justice committee last week to bolster her contention that she was improperly pressured last fall to intervene to stop the criminal prosecution of Montreal engineering giant SNC-Lavalin.

Prime Minister Justin Trudeau's former principal secretary, Gerald Butts, who had earlier testified in response to Wilson-Raybould's allegations, has submitted additional documentation to the committee related to the SNC-Lavalin affair.

Those documents were expected to be released publicly by the committee later Tuesday.