But Stéphane Dion, who leads the Liberals and who would become the coalition’s prime minister, dismissed the idea of working with Mr. Harper and said the Conservatives’ budget was unlikely to satisfy the opposition’s economic demands.

“We do not want any more of his words, we don’t believe them,” Mr. Dion told reporters before the closed doors of the House of Commons. “We want to see changes, monumental changes.”

Opposition leaders said they would continue to try to form a new coalition, and strongly criticized Mr. Harper’s attempt to thwart them. “He’s put a lock on the door on the House of Commons,” Jack Layton, the leader of the New Democrats, told reporters. “He refuses to face the people of Canada through their elected representatives.”

The opposition’s move to form a new coalition has, in turn, elicited sharp criticisms from some Conservative members. “That is as close to treason and sedition as I can imagine,” Bob Dechert, a Conservative member, said Wednesday, echoing a refrain heard widely in Alberta, the prime minister’s home province.

Technically, what Mr. Harper did was to “prorogue” Parliament, a move that stops all actions on bills and the body’s other business, and thus goes well beyond an adjournment (which was not available to Mr. Harper in any event, as it requires parliamentary approval). It is not unprecedented  prorogation is used occasionally to introduce a new legislative agenda  but this is the first time any Parliament members or constitutional scholars here could recall the maneuver being used in the midst of a political crisis and over the objections of Parliament.

Mr. Harper declared the parliamentary suspension after a two-and-a-half hour meeting in Ottawa with Ms. Jean. While no governor general has ever previously rejected a prime minister’s request to prorogue Parliament, several constitutional scholars said Mr. Harper was the first one to have asked permission when he did not have the support of the legislature.

“That’s why they spent two and a half hours talking,” said C. E. S. Franks, a professor emeritus of political studies at Queen’s University in Kingston, Ontario.