Quebec's intergovernmental affairs minister is calling the federal government's foray into a court challenge of Bill 99 a direct attack on the legal rights of Quebecers.

Bill 99 is the provincial law passed 13 years ago asserting Quebecers' right to decide the rules of secession from Canada.

Alexandre Cloutier said the Parti Québécois will table a motion in the coming days at the national assembly, and that Ottawa has no business challenging what he calls one of the most important laws Quebec has ever adopted.

“The federal government wants to invalidate the ability of the national assembly to consult its own people on the [referendum] question,” said Cloutier at a news conference in Quebec City on Sunday.

"Obviously, they want to make sure we're never going to get our country."

On Wednesday, the government filed a legal intervention in a case before Quebec's Superior Court that challenges Bill 99.​

Bill 99 was passed in 2000 by the then PQ government under Lucien Bouchard as a response to the federal Clarity Act. It states that only Quebecers can decide whether the province has the right to secede.

Cloutier also criticized the federal government for calling into question the 50 per cent plus one vote rule in a possible referendum — something he said is "universally" recognized.

Other provincial parties back PQ

Other Quebec political leaders are also lashing out at the federal government for stepping into the legal battle over the rules for secession.

The Quebec Liberal Party's Philippe Couillard, Coalition Avenir Québec's François Legault and Québec Solidaire's Françoise David have all lined up to express their indignation.

However, Liberal MP Stéphane Dion — the man behind the Clarity Act — said the federal government has always opposed Bill 99, and that the Quebec government is manipulating the court system.

"You see the hypocrisy of the Quebec "péquiste" government. Facing the judge, they are playing down their own law, but in public they will say 'we have the right to secede' and so on. They will play a double talk and we should denounce that,” said Dion.

The leader of the official opposition — the NDP's Tom Mulcair — said he believes the Conservative government should stay out of the Bill 99 court case.

Mulcair said his party's position on the matter, outlined in the Sherbrooke Declaration, recognizes a vote of 50 per cent plus one in a referendum as being enough to spark negotiations for secession.

"If we want to move forward from this, we've got to stop fighting the quarrels of the past. This court case is not going to change anything. The Supreme Court ruled on this in 1998. That's the law of the land and that's what we should be paying attention to," said Mulcair.

The Bill 99 court case is expected to be heard sometime in 2014.