The Ontario government is pushing back the rollout dates for the Ontario Retirement Pension Plan to give larger businesses more time to enrol.

The new provincial plan would cover some three million Ontarians who don't have workplace pensions.

Workers at large companies (with 500 or more employees) were scheduled to start contributing in January 2017. But Finance Minister Charles Sousa said Tuesday businesses have been asking for more time, and announced contributions won't begin until 2018.

"We have heard from businesses," Sousa said in a midday speech in Toronto Tuesday.

"We are giving employers more time to prepare and about 400 companies involved will have the extra time they've asked for."

There's no delay for smaller firms. Medium-sized companies (wth 50 to 499 employees) are still scheduled to start contributing in 2018 and small businesses (with fewer than 50 employees) in 2019.

Following Sousa's speech, NDP finance critic Catherine Fife questioned the Liberals' commitment to the pension plan.

"People deserve retirement savings opportunities. This is what was promised by the Liberal government," Fife told reporters. "Their backtracking is an indication as to really how truly committed they are to the plan."

Earlier Tuesday, Premier Kathleen Wynne said her government is "not going to abandon what we know is important to the people of Ontario, a decent retirement at the end of their working life."

CPP reform also possible

In a joint statement released Tuesday, Sousa, his Associate Minister Mitzie Hunter and Federal Finance Minister Bill Morneau said the two levels of government will also be "working intensively with other jurisdictions" to look at "a range of potential" changes and reforms to the Canada Pension Plan.

"To this end, the governments of Canada and Ontario will work with other provinces and territories to develop options for CPP enhancements by the end of May in time for the Federal-Provincial-Territorial Finance Ministers meeting in June 2016," the statement reads.

If provincial agreement on enhancement of the CPP is not reached, the statement went on, the federal government "acknowledges the government of Ontario's objective to move forward with the ORPP.

"As such, the federal government has agreed to facilitate plan registration and data sharing arrangements, and will work with Ontario to ensure that key elements of plan administration, such as the collection of employer and employee contributions, are completed efficiently and cost-effectively."

The joint statement and pledge by the federal Liberals to work with Ontario to implement its provincial plan marks a change from the previous federal government's position on the ORPP.

Last August, then-prime minister Stephen Harper said he was "delighted" that his government's unwillingness to work with Ontario was making it more difficult to implement the plan.

Calling the provincial plan "an enormous tax increase," Harper said his government would continue to fight it.

Two months later, Harper's Conservatives lost the federal election to Justin Trudeau's Liberals.