He said he is "uncomfortable" with the expression "shadow cabinet" - the nearly 200-year-old British parliamentary term for the opposition's alternative cabinet whose members face off with ministers during question period.

Explaining a desire to be inclusive, to tap into the governing experience of caucus members and to foster team work, Dion announced a two-layer committee system on top of a traditional, albeit longer-than-usual list of 47 opposition critics.

He and deputy leader Michael Ignatieff will chair a 20-member priorities and planning committee that includes the chairs and vice-chairs of four caucus committees, totalling 52 MPs, plus former prime minister Paul Martin and former interim party leader Bill Graham as special advisers. They will meet weekly.

The committees are grouped around three themes Dion highlighted during his leadership campaign plus "Canada and the world," chaired by Toronto MP Bryon Wilfert, one of Dion's early leadership supporters in caucus.

The three others are economic prosperity, chaired by Toronto MP John McKay; social justice, chaired by Toronto MP and leadership candidate Ken Dryden; and environmental sustainability, chaired by Toronto MP John Godfrey, the former environment critic replaced by Ottawa MP David McGuinty.

The structure left some MPs wondering privately who will be calling the shots and complaining there will be even more meetings on top of the weekly Liberal caucus gathering plus Commons committee meetings.

"We have an opportunity to work as equals with a lot of collegiality and then to tap into the talents and skills of everyone as long as we are not all over the map and we have a strong focus," said Dion, who admitted he has heard the doubters.

He noted more than 70 Liberal MPs have at least a decade of experience in Parliament and 29 are former cabinet ministers.

Dion announced a 10-member group of mentors for new candidates in the next election who will be running to replace at least 15 current members who will be retiring. The group, headed by Gerard Kennedy, will help train candidates to campaign.

"I want to be sure that when the next election comes - we don't know when, we don't want an election, but we need to be ready - that our Liberal candidates without campaign experience will benefit from the rich experience of my caucus," Dion said.

His critics will be poised to face off against Prime Minister Stephen Harper's 30-member cabinet. But some of the critics are listed by theme, rather than department. For example, former justice minister Irwin Cotler is the "human rights" critic, while the justice critic's job went to Montreal MP Marlene Jennings, another of the 10 MPs who supported Dion's long-shot leadership bid from the get-go.

Among the most senior critic posts, Dion left Toronto MP John McCallum in finance, awarded industry to leadership candidate Scott Brison, and appointed Montreal MP Denis Coderre to replace Vancouver MP Ujjal Dosanjh in defence. He moved Dosanjh to foreign affairs.

The timing of the Dosanjh appointment appeared to be last- minute, as the list that appeared on the Liberal Party website as Dion began his news conference had Wilfert in defence and Dosanjh without a role. But the list was pulled and replaced within minutes.

Liberal Party spokesman Tait Simpson said the technicians writing the list for the Web made that and other mistakes by putting the wrong names in some slots. He denied speculation the party had posted an early list that Dion changed at the last minute.

"It was completely our error," he said, noting the correct list was posted within nine minutes.

Among newcomers as prominent critics are Omar Alghabra in citizenship and immigration and Navdeep Bains in international trade.