TORONTO - Ontario's opposition parties say the government is blocking attempts to call more witnesses before a committee looking into the Liberals' decision to cancel two gas plants, which will cost taxpayers up to $1.1 billion.

The Progressive Conservatives and New Democrats want the committee to hear from former Dalton McGuinty staffer Laura Miller and her computer tech boyfriend about the wiping of computer hard drives in the premier's office.

The opposition parties dominated the committee until the Liberals won a majority in the June 12 election, so the government now has control of the agenda and doesn't want to hear from more witnesses.

Liberal house leader Yasir Naqvi says Premier Kathleen Wynne has made it clear she thinks its time for the committee to write its report on the cancellation of the gas plants in Oakville and Mississauga prior to the 2011 election.

The Opposition is also calling on the Liberals to release the report of another committee that was looking into financial irregularities at the province's Ornge air ambulance service.

That committee had actually written its report but never had a chance to table it in the legislature before the election was called, but a frustrated former Tory who did not run for re-election did leak a copy of the Ornge report to the media.