UPDATE: PCs plan to introduce back-to-work legislation for OPG workers on Monday

Toronto's Manby transformer station

The Ford government is heading back to Queen's Park on Monday, interrupting their Christmas break, in order to ensure the lights and heat stay on for the entire province.

They made the announcement Friday evening after the union representing 6,000 Ontario Power Generation workers has filed a strike notice.

The Power Workers Union informed the OPG late Friday that it will begin the 21-day shutdown of its power plants.

But Energy Minister Greg Rickford said that outages could occur in seven to 10 days.

"Because they have to start taking steps towards that 21st day," he said. "The government has to prepare for itself, be prepared to take whatever steps are required to deal with this matter swiftly."

"We obviously don't want that scenario to occur."

The plants make up for 40 per cent of Ontario's electricity supply.

After the union informed OPG, Government House Leader Todd Smith confirmed the emergency session.

"Given the uncertainty created by the impasse between Ontario Power Generation and the Power Workers' Union, it is the intent of the government to reconvene the 42nd Parliament at 1 pm on Monday, December 17th for the purposes of introducing legislation to ensure that Power Workers remain on the job," he said in a statement. 

It's expected the bill will pass on Thursday.

The NDP, however, says they will do whatever is necessary to stall the legislation and use whatever tools they have at their disposal. 

They have called the Ford government's tactics "unnecessarily alarmist."

The Power Workers' Union has been without a deal since March 31st.

- With files from Jackie Rosen