OTTAWA -- Justin Trudeau frankly admitted Thursday that his government bungled the launch of its electoral reform initiative by leaving the impression it was planning to rig the way Canadians vote to benefit the governing Liberals.

The prime minister's candid admission came as the government moved to cede control over the process that is supposed to come up with an alternative to the current first-past-the-post voting system.

Democratic Institutions Minister Maryam Monsef announced two major concessions Thursday, one of which was to give up the Liberal majority on the all-party committee that is to explore alternative voting systems.

Monsef also opened the door to an eventual referendum, leaving it up to the committee to advise on the best way to consult Canadians on whatever alternative it winds up recommending.

It was a significant change of heart for the Liberals, who've been pilloried for their insistence on retaining the government's traditional majority on the committee and for refusing to commit to a referendum.

Opposition parties have accused the government of stacking the deck to ensure the committee ends up recommending a ranked-ballot system, which Trudeau has indicated in the past is his personal preference and which opponents maintain would unfairly boost the Liberals' chances of re-election.

Trudeau said his government had been acting more like the previous Conservative regime, which he's frequently derided for ramming through changes to election laws without any support from other parties.

"We heard the opposition's concerns that we were perhaps behaving in a way that was resembling more the previous government than the kind of approach and tone that we promised," Trudeau said.

"We're happy to demonstrate that absolutely, we're looking for ways to better work with our colleagues in the House, to better hear from Canadians and their concerns, and I look forward to working towards reforming our electoral system with the input of as many Canadians -- including opposition parties -- as possible."

Trudeau did not directly promise a referendum, but said all Canadians need to be involved in the discussion.

"It's important that we hear not just from political parties and their opinions, but from all Canadians as to how we're going to establish better governments, better governance for our country."

The concessions came in response to an NDP motion calling for the committee's membership to reflect each party's share of the popular vote in last fall's election.

"The logjam is broken, the impasse has been overcome, at least on the process," said NDP democratic reform critic Nathan Cullen.

"The biggest winner out of this is Canadians who want to see our voting system changed in a positive and hopeful way and that the parties work together."

But the Conservatives, who've resisted any changes to the electoral system and have been demanding a referendum, were far from mollified.

Conservative democratic reform critic Scott Reid said cabinet will still make the final decision on any change to the voting system. And he accused the government of using the committee to "fritter away time" so that there won't be time to introduce any new electoral system other than the ranked ballot system the Liberals want.

Reid also accused the Liberals and NDP of cooking up "a backroom deal" on the committee membership, without consulting the official Opposition.

"Any talk of inclusiveness is just nonsense."

Under the government's original plan, the committee would have been composed of six Liberals, three Conservatives and one New Democrat, with a Bloc MP and May on the committee but not entitled to vote.

The NDP motion changes that to five Liberals, three Conservatives, two New Democrats, one Bloc MP and May -- all with voting rights -- and requires the committee to begin meeting within 10 days.

The committee is to explore other voting systems that would ensure that a party's share of seats in the House of Commons is more reflective of its share of the popular vote. The current system is widely criticized for routinely delivering a majority of the seats to a party that wins less than 40 per cent of the vote, over-representing regionally-concentrated parties and under-representing small national parties.