Ottawa, Dec. 2 : In a political coup, Canada''s three opposition parties have joined hands to oust the just elected minority government of .

Leaders of the country''s three main opposition parties presented their plan to topple Harper''s minority government at a press conference in Ottawa late on Monday afternoon.

According to the Globe and Mail, the Liberal Party, the New Democratic Party and the Bloc Québécois publicly signed a coaltion accord and sent a letter to Governor-General Michaëlle Jean saying the opposition has lost confidence in the Conservatives.

The proposed coalition government between the Liberals and the New Democratic Party would last until June 2011, but the Bloc is only pledging support for 18 months, the paper further said.

The cabinet will have 18 ministers from the Liberal Party and six from the NDP. It will be the first time since 1926 that a Canadian government will be replaced without an election.

In the 308-member House of Commons, the ruling Conservative Party has 143 MPs, the Liberal Party 77, the NDP 37 and the Bloc Quebecois 49.

Under the plan, Liberal Leader Stéphane Dion would become prime minister until May, when his successor would take over.

The Liberals and the NDP have agreed to a 30 billion Canadian dollar stimulus package as part of a tentative coalition deal to oust the Harper government, the paper quoted a source in the Liberal Party, as saying.

"Canadians elected 308 members of Parliament in October, not just Stephen Harper. We are ready to form a new government that will address the best interests of the people instead of plunging Canadians into another election," Liberal Party chief Dion, New Democratic Party chief Jack Layton and Bloc Quebecois chief Gilles Duceppe told reporters here.

The coalition accord stipulates that the prime minister and finance minister would be Liberals, with six of 24 cabinet positions filled by New Democrats.

Earlier Monday, the three candidates running for the Liberal leadership emerged from a closed-door caucus meeting to endorse Mr. Dion as head of the proposed coalition government, which they said would pour billions of dollars into the economy.

Standing side-by-side, Michael Ignatieff, Bob Rae and Dominic LeBlanc made clear they see no scenario in which the Conservative minority can remain in power.

"I support the accord because it''s fiscally responsible, it provides responsible economic leadership in tough times and it also conserves the basic principles of national unity, equality, that our party has always believed in," Mr. Ignatieff said. "We are at one, the three of us, that the only person that can lead the country is the duly elected leader of the party, Mr. Stéphane Dion."

Liberal MP Martha Hall Findlay said that even if the Conservatives put forward an economic-stimulus package now, it would have no credibility and the opposition would reject it.

Only minutes later, in Question Period, Dion demanded Prime Minister Stephen Harper provide an opportunity for the opposition to vote no-confidence in his government.

Harper replied that it is the Liberal Leader, not he, who is playing political games.

The coaltion deal includes a multibillion-dollar stimulus package for the troubled economy. Liberal MP John McCallum said the stimulus plan under consideration could include cheques for Canadian households as well as infrastructure spending and aid for the forestry and manufacturing sectors.

McCallum also noted that a Liberal-led government would run a short-term deficit but be determined to balance the budget as quickly as possible.

Opposition sources said the goal of the opposition''s letter to the Governor-General is to inform Ms. Jean that a viable alternative to the current government exists within the current Parliament.

Harper, however, has raised doubts about the legitimacy of a coalition government, and is expected to urge Ms. Jean to call an election in the event of a defeat in the House.

The opposition letter, in that context, is designed to persuade Ms. Jean to reject the Tory push to send Canada to the polls for a second time in three months.

In the Oct 14 general election, Prime Minister Stephen Harper''s Conservative Party was returned with a tally of 143 seats in the 308-member House of Commons. But it fell short of the 155-seat majority mark, leading to the current crisis. (ANI)