It's happened before, with the Conservatives' controversial Bill on Labour laws. Hugh Segal led the objection against his party's position on labour laws, but he was a Red Tory.There was a similar case in the 90's where the senate rejected an abortion bill introduced by Kim Campbell as a response to the SCC invalidating the abortion laws
Could conservative senators vote against a bill coming from their own party ?
http://www.cbc.ca/news/politics/con...mendment-guts-union-disclosure-bill-1.1367879
'[Liberal Senator] Cowan praised the Senate for what he called doing its job by applying sober second thought to a flawed bill. "If the NDP had its way, there would be no Senate and Bill C-377 would have been the law of the land months ago. It was Liberal senators, supported by a handful of brave Conservative senators, who gutted this bill," he said.'
Conservative senators in favour of Segal amendment
Josée Verner
Gerald Comeau
Nancy Ruth
Nancy Greene
Richard Neufield
Daniel Lang
Jacques Demers
Judith Seidman
David Braley
Don Meredith
Larry Smith
Betty Unger
JoAnne Buth
Norman Doyle
Paul McIntyre
However, according to the article,
"Once the bill arrives back in the House of Commons, Segal's amendment can be approved or rejected, and then the bill would be sent back to the Senate once again. However, the bill won't seesaw back and forth between House and Senate endlessly. The convention established over time is that the Senate eventually bows to the will of the elected chamber. "
But given the questions asked at the Senate hearings on C-36, I don't hold much hope of a repeat.