The fate of $700 million in South Australian infrastructure projects may rest on the attitude opposition MPs take in a parliamentary committee hearing, the state government says.

The Public Works Committee will meet on Thursday as it considers a long list of projects, including the upgrade to the Queen Elizabeth Hospital, an irrigation scheme in Adelaide’s north and major public transport initiatives.

Transport and Infrastructure Minister Stephen Mullighan says Liberal MPs pulled out of a similar committee hearing last week, preventing discussions from proceeding and if similar action occurs on Thursday it could stall the projects at the final hurdle.

“We are ready to appoint contractors on many of these projects and get South Australians working, but the Liberals are trying desperately to block these crucial investments,” Mr Mullighan said.

Opposition infrastructure spokesman David Pisoni was among those to leave last week’s committee hearing over the government’s refusal to reveal the cost of buying emergency generators to help avoid blackouts.

“Jay Weatherill’s claim he is keeping the cost secret because he’s got a great deal is laughable,” Mr Pisoni said in a statement on Thursday.

But Mr Pisoni indicated he would attend Thursday’s meeting after a promise from Mr Mullighan that the government will release the cost of the generators once a commercial-in-confidence period ends in a matter of weeks.

“This information will enable all South Australians to know whether Jay Weatherill has blown the budget on his half-baked $550 million energy plan,” Mr Pisoni said.