The Bloc Quebecois has lost its bid to re-write the rules for Quebec secession — but not before inflicting considerable political damage on the NDP.

A Bloc motion calling for repeal of the Clarity Act was easily defeated late Wednesday by a vote of 283-5, with Conservatives, New Democrats and Liberals all opposing it.

There is no surprise in the motion's crushing defeat, but the Bloc succeeded in exposing divisions within the NDP — the BQ's arch-rivals in Quebec — and prompted New Democrat MP Claude Patry to defect to the Bloc last week.

The motion also provided fodder to federalist rivals to accuse the NDP of pandering to separatists with its proposed alternative to the Clarity Act.

The Clarity Act stipulates that an undefined clear majority of Quebecers would have to vote Yes on a clear question to secede before the federal government would agree to negotiate terms of a national divorce.

In response to the Bloc motion to repeal the act, the NDP proposed its own "unity bill" to replace Clarity. It says that a bare majority of 50 per cent plus one vote would be sufficient to trigger negotiations on secession, provided that the referendum question was clear and there were no irregularities in the vote.