Parti Québécois Leader Bernard Landry has dropped a bombshell, announcing that he is leaving politics after earning a score of 76.2 per cent in a confidence vote.

Landry, who has led the party since 2001, had said he would stay on if he scored at least 76 per cent in Saturday's vote at a PQ convention in Quebec City.

But after hearing the result, the 68-year-old said he felt he didn't have enough support to continue as PQ leader and was stepping down.

"It breaks my heart to tell you this, but I'm doing it in the national interest," said Landry, who choked up as he told about 1,500 PQ members that his days in politics were over.

"I'm sorry to do this."

The PQ is redesigning its platform to make a much more aggressive drive for sovereignty, guaranteeing another referendum if the party wins the next election.

It is also poised to capitalize on the Quebec public's anger at the Liberals over the federal sponsorship scandal.

But Landry said that with nearly one member in four against him, he simply didn't have the backing he needed to get the job done.

"The next person who leads the sovereigntist troops must be strongly supported without equivocation," Landry said.

Landry, who became premier after Lucien Bouchard resigned in 2001, lost the 2003 provincial election to Jean Charest's Liberals.

Since then, a series of people within the PQ – including former deputy premier Pauline Marois and a founding member of the party, Marc Brière – have called for a leadership race.

The last one was in 1985 when Pierre Marc Johnson succeeded René Lévesque. Jacques Parizeau, Lucien Bouchard and Landry were each acclaimed as leader.

Saturday's vote marked the first leadership review Landry had faced since the 2003 election.

Landry's announcement left many supporters in tears and prompted all PQ legislators to gather for an emergency meeting.

The PQ caucus will meet Tuesday to pick an interim leader, party officials said.

There's no obvious successor within the party.

Meanwhile, the head of the federal Bloc Québécois, Gilles Duceppe, urged Landry in a statement to stay on as leader.

"Bernard Landry is still the man for the situation and [Duceppe] is asking him to reconsider his decision," the statement said.

Prime Minister Paul Martin extended his best wishes for Landry in his retirement.

"While Mr. Landry and I have fundamentally different views about the future of Quebec and the unity of our country, his commitment to his province – as a Member of the National Assembly, as Minister of Finance and ultimately, as Premier – is beyond question," Martin said in a statement.

Landry was born in Saint-Jacques-de-Montcalm on March 9, 1937. He studied law at the University of Montreal, then economics and finance at the Institut d'études politiques in Paris before being called to the Quebec Bar in 1965.

After helping found the PQ in 1968, Landry was defeated when he ran for the National Assembly under the fledgling party's banner in 1970.

Landry was successful, however, in the 1976 election that swept Lévesque to power, and served in Lévesque's cabinet as minister of state for economic development.

He had a second successful run in 1981, but sat out the 1985 and 1989 elections as the PQ's fortunes sagged. While the Liberal government of Robert Bourassa was running the province, Landry went into a political exile of sorts, teaching business at the University of Quebec's Montreal campus.

Landry returned to political life in 1994, winning a seat in the National Assembly and serving as deputy premier under Parizeau.

Landry kept the deputy position after Parizeau, embittered by the failure of the 1995 referendum, handed over the party leadership to Bouchard. He added the Finance portfolio to his responsibilities in early 1996.

When Bouchard abandoned politics, Landry reached the apex of his political career: he ran unopposed for the PQ leadership, and became the premier.