Jean Chrétien officially kicked off the Liberal convention Friday with a scathing assessment of Conservative Prime Minister Stephen Harper's foreign policy and economic management.

With his trademark mix of humour and folksiness, the former prime minister revved up Liberal troops meeting in Vancouver by skewering Harper as a leader who's gone missing on the international stage and bungled the economic crisis.

Chrétien recounted how Harper, when in opposition, used to malign Canada as a welfare state while singing the praises of the George W. Bush's Republican regime in the United States.

But now that the Republicans have fallen out of favour and the world economy has melted down, Chrétien said Harper is trying to take credit for the very Liberal policies he used to trash.

Chrétien mocked Harper for seeking out interviews with American media to "brag" that Canada is weathering the economic tsunami better than most because its fiscal house was in order and its banking system strong and stable. Chrétien took credit for both, noting that it was his Liberal government that refused to allow bank mergers and erased a $42-billion deficit inherited from Brian Mulroney's Tories.

"We turned Canada into a success story that even Stephen Harper is bragging about. Soon, very soon, Liberals will be called again to fix up another big Tory mess," Chrétien said as Liberals prepared to officially make Michael Ignatieff their leader.

Earlier Friday, in Edgeley, Sask., Harper was asked whether he had any words for Liberals enjoying lofty poll numbers and preparing to adopt a more aggressive posture in Parliament.

Harper said now's the time for parties to work together.

"What we're looking for from Ignatieff and the other parties is, obviously, an opportunity to work together to advance the interest of the country," he said.

Then Liberal leader Stéphane Dion and the man who would replace him, seen at an election rally in Ontario in September 2008. (Ryan Remiorz/Canadian Press)

When the convention was called last fall in the wake of the party's worst electoral showing in a century, expectations were that it would be the culmination of a wide-open and exciting leadership race.

But that race never materialized and Ignatieff is to be formally acclaimed leader on Saturday. He's been filling that role since December when Stéphane Dion stepped down.

The more than 1,500 delegates will have the opportunity to vote for their new leader, but Ignatieff's will be the only name on the ballot.

There will also be some discussion of policy proposals, but organizers have been careful to keep the focus on showcasing the party's new face rather than getting bogged down in possibly controversial policy discussions.

"We are happy to have a debate on the issues, and Mr. Ignatieff is more than ready to do that over the next several months," Liberal Senator Dennis Dawson said.

Ignatieff credited Harper for the Liberal party's renewed unity and improved fundraising.

Harper's government sparked a parliamentary crisis last fall when it used a fiscal update to try to financially hobble opposition parties.

That prompted the three opposition parties to band together in a bid to form a coalition government and ultimately led to Ignatieff taking over the Liberal reins from Dion.

"Mr. Harper dislodged a snowball that turned into an avalanche," Ignatieff told reporters on Friday. "The Liberal party responded as it always does when faced with a national crisis — it got its house in order.

"We now have a party basically ready to fight an election and some of the credit has to go, ironically, to my chief rival Stephen Harper," Ignatieff said.