Liberal Leader Stéphane Dion continued to paint the Conservatives as untrustworthy on Wednesday, repeating his demand that Prime Minister Stephen Harper dispel allegations his party broke election spending laws.

"Open the books, show invoices," Dion said in St. John's while speaking at a three-day caucus meeting that wraps up on Thursday.

"For the prime minister, it's easy to dismiss this claim — just open the books."

The issue involves Conservative party spending during the campaign for the 2006 parliamentary election.

The party gave $1.2 million to local candidates who hadn't reached their spending limits. That money was then returned to the party, which spent it on regional television and radio ads.

Financial agents for at least 35 of those candidates had asked to be reimbursed for those expenses (candidates who get 10 per cent of the votes in their riding get a portion of their election expenses returned).

Elections Canada refused, saying the party paid for the ads, not the candidates.

Unless the Conservative party can prove the money was legitimately used by the candidates, the total campaign funding could exceed the $18.3 million spending limit.

Dion said Wednesday that unless Harper showed invoices for election spending within days, the Liberals would ask a parliamentary committee to review the issue.

"I am asking for evidence," he said. "Otherwise, we'll go [to] committee when the House [of Commons] opens and request the books be opened."

No trust in government: Dion

The Liberal leader also hammered away at the issue of Conservative trustworthiness, contrasting himself and Harper as well as the Liberals and the Tories.

Canadians are "entitled to have a federal government, a government of Canada, and a prime minister they can trust," he said.

"The current government and prime minister are a big disappointment about that.… The lack of trust that we see every week, always lack of transparency and trust."

He continued to drop references to a possible fall election, saying the party is ready whether Canadians go to the polls "in the fall or in two years."

Dion has said he won't hesitate to vote against a throne speech if it doesn't include a comprehensive plan to tackle climate change and a commitment that Canada's combat mission in Afghanistan would end by February 2009.

He included a welcome to the media in his speech, which drew applause and laughter from caucus members. Earlier in the summer, members of the media were ordered out of a Charlottetown hotel where the Conservatives were holding their caucus.

"Don't worry, we're not the Conservatives, we will not send the police to hurt you," joked Dion.

On Tuesday, Dion said the Liberals would honour the Atlantic accords, the 2005 deals that protect offshore energy royalties from federal clawbacks.

In the leadup to the 2006 election, Harper promised to exclude natural resource revenue from the equalization formula. The 2007 federal budget included a formula that included half of those revenues.

Dion told reporters there was a "breach of trust."

With files from the Canadian Press