Opposition parties at Queen’s Park want the integrity commissioner to become involved in the investigation into the cancellation of two gas plants.

The Progressive Conservatives want the commissioner look into whether Dalton McGuinty’s Liberals threatened the Speaker of the legislature to change a ruling against the government.

Newly released emails show senior Liberals in McGuinty’s office tried to get Speaker Dave Levac to change his preliminary finding that then-energy minister Chris Bentley was in contempt for not releasing all documents on two cancelled gas plants.

The Tories said discussions about trying to intimidate the Speaker shows the Liberals will stop at nothing to try and bury the scandal over their decision to cancel gas plants in Oakville.

Meanwhile the NDP  plan to call two McGuinty staffers who talked about pressuring the Speaker to change his mind in an email to appear before the justice committee hearings into the cancelled gas plants.

Levac says he never felt political interference that would prevent him from making decisions.