Opposition MPs are fighting to get an opposition day on May 19, and that could provide an opportunity for a non-confidence motion that would defeat the government.

In the meantime, Parliament faces the possibility of gridlock in a dispute over the issue, which first sprang up Monday night.

The Liberals stripped the Conservatives, Bloc Quebecois and NDP of their informal but regularly scheduled opposition days. Such days are held to allow the opposition parties to introduce motions.

Liberal House Leader Tony Valeri made the move after hearing that Conservatives wanted to pass a motion locking those days in. They particularly wanted opposition days on May 11 and 18 -- days considered possible trigger points for a June election.

The opposition parties fought with the Liberals over the opposition day issue at a Commons procedures and House committee meeting on Tuesday.

Jay Hill, the Conservatives' house leader, moved that the chairman of the committee, Liberal Don Boudria, recommend the House of Commons designate May 19 as a Conservative opposition day.

That meeting ended inconclusively, said CTV's Craig Oliver.

"The government wants (the opposition) to defeat them on the budget bill," Oliver reported, noting that would create a political headache for the opposition.

Alternatively, if the government can stack all the opposition days towards the session's end in late June, that would mean an election in the prime summer holiday time of July, he said.

During a Newsnet appearance Tuesday, Conservative Leader Stephen Harper said the government is trying to avoid any vote on a significant matter.

"Obviously I have to judge what Canadians are telling me, but what this tells me is the Liberals don't believe they have the confidence of Canadians. They are scared to death of an election."

Asked if staving off a non-confidence vote until late June would prevent an early summer election, Harper said, "I wouldn't put any bets on it."

In appearances before reporters, Bloc Quebecois Leader Gilles Duceppe and NDP Leader Jack Layton both condemned the government for its move on the opposition days.

Other business

To add to the Liberals' woes, the Bloc Quebecois brought in a motion Tuesday night asking the Liberal Party to set up a multi-million-dollar trust fund to hold any potentially ill-gotten sponsorship money. The motion passed 157-119.

Another hot issue this week was the allegation by former Liberal insider Warren Kinsella that he received an intimidating phone call before he testified at the Commons public accounts committee on Monday.

The caller allegedly said that former public works minister David Dingwall, now CEO of the Royal Canadian Mint -- would deny Kinsella's accusations. Kinsella was Dingwall's chief of staff.

CTV's Mike Duffy said the identity of the alleged caller will be revealed Wednesday.

However, Canadian Press reported late Tuesday night that the man's name is Frank Schiller, a former colleague of Kinsella's in Dingwall's office.

Schiller is currently a principal with IGRG (Industry Government Relations Group), an Ottawa consulting firm.

Conservative MP John Williams, who chairs the committee, told CP a four-member steering committee discussed the phone call in a closed meeting on Tuesday.

The full committee will decide on Wednesday whether to launch a formal investigation, he said.

With a report from CTV's Craig Oliver and files from The Canadian Press