NDP Leader Thomas Mulcair speaks to the media outside the New Democratic Party (NDP) caucus strategy session on Parliament Hill in Ottawa, January 17, 2013.
"The Clarity Act is not clear and it settles nothing," Mulcair said Monday, adding his party wants to improve rather than repeal it.
Mulcair said "of course" the NDP will have a free vote on C-457, even though his caucus includes Quebec MPs who've supported separatist causes in the past and hard-left MP Libby Davies, who opposed the Clarity Act when it was introduced.
A party official insists caucus united.
The Clarity Act requires any provincial independence referendum to ask a "clear question" and get a "clear majority" in favour of secession before the feds begin negotiations on separation.
That's a non-starter for Bloc Leader Daniel Paillé.
"I'll never accept the tutelage of the Parliament of Canada over the referendum law in Quebec," he said.
With the Conservatives and Liberals dead-set against the Bloc bill, the Clarity Act will survive, but the controversy continues for the NDP.
Mulcair said his party supports the Sherbrooke Declaration, which states that Quebec can quit Confederation if 50% plus one vote in favour of separation during a referendum.
Liberal MP Stephane Dion says such a "flimsy" majority isn't compatible with the Clarity Act.
"If 50% plus one constitutes a clear majority, what constitutes an unclear majority?" he said, noting that the NDP sets a higher threshold for amending its own constitution than for Quebec separation.