TORONTO - The governing Liberals are trying to sweep the Ornge scandal under the rug by blocking a legislative committee from continuing its probe of the province's troubled air ambulance service, the opposition charged Thursday.

The Progressive Conservatives and New Democrats say the governing Liberals are refusing to agree to extra sittings for the committee that's examining Ornge, which is under a criminal probe for financial irregularities.

There are only two days of hearings left before the legislature breaks for the summer and the committee needs to continue its work, they said.

The government is trying to shut down the committee's work because it doesn't want the lobbying efforts of Liberal insiders who worked for Ornge to be exposed, said Tory Frank Klees.

"The reason the government doesn't want us to continue with these hearings is because it's coming far too close to them," Klees said. "Too close to ministers, too close to the premier's office, too close to their inside friends who clearly had a very important role to play."

Government house leader John Milloy dismissed the accusations, saying the committee has already sat for 29 hours and heard from 33 witnesses.

It's the Tories who are stonewalling the work of the legislature by forcing 30-minute division bells as often as possible as a delay tactic, he said.

"I don't know if I'm the only one here who finds it ironic that the honourable member whose party has been blocking legislation, has been tying up committees ... that he has the gall to stand here today and somehow criticize us as blocking a committee," Milloy said in the legislature.

Klees said his party is ringing the bells to protest the government's refusal to strike a special committee on Ornge -- even though a majority of the legislature voted to support it -- or expand the mandate of the current committee, which would allow them to hold more hearings.

"We don't have any other tool available to us as the Opposition," he said.

NDP health critic France Gelinas said the committee members need to question more key witnesses, including ousted Ornge CEO Chris Mazza.

The committee has heard conflicting testimony from other former Ornge executives and government officials, so it needs more time to get at the truth, she said.

The public needs to know exactly what went wrong at Ornge, Gelinas said. Some say it was poor oversight, while others say it was bureaucrats not doing their jobs.

Some say it was lobbying within the party that allowed Ornge to move ahead with its for-profit plans that went completely off the rails, she said.

"There are a number of theories out there, but they are just that," Gelinas said.

"Only once we have the opportunity to hear from everybody can we make an informed decision as to what went wrong, how do we correct it, how do we turn the page."