TORONTO -- Ontario's Progressive Conservative government will hold a rare Saturday sitting of the legislature to speed up passage of a controversial bill to slash the size of Toronto city council.

A source confirms to The Canadian Press that legislators will be called back to Queen's Park Saturday at 1 p.m. to help speed up debate on Bill 31, dubbed the Efficient Local Government Act.

The bill re-introduces legislation that was struck down by an Ontario Superior Court judge as a violation of the charter rights of voters and candidates in the city's upcoming municipal election.

The new legislation invokes the notwithstanding clause to override that court decision -- the first time Ontario's government has taken the measure.

The news of a Saturday sitting came hours after the official legally responsible for running Toronto's election said every delay resulting from the battle between the province and the city affects her ability to ensure fairness in the Oct. 22 vote.

Toronto clerk Ulli Watkiss says that's true whether the election involves 25 or 47 wards.

"We have hit a tipping point," said Watkiss. "Both scenarios are becoming virtually impossible for us to carry out."

Ontario's legislature is scheduled to adjourn for two days early next week for the annual International Plowing Match in Pain Court, Ont., before resuming its regular sitting.

The event, which is generally attended by all legislators, would add even more time before the bill is passed.

Both Ontario's NDP and Liberal Party have vowed to introduce amendments to the bill that could potentially delay its passage.

The NDP said Thursday it will challenge the bill under rules that preclude legislators from introducing substantially the same bill twice in one session and bar the legislature from debating an item currently before the courts.

In a statement Thursday night, Tory House Leader Todd Smith confirmed the government is willing to sit this weekend to move the legislation forward.

"While the NDP are playing procedural games to delay the passage of the Efficient Local Government Act, the PCs are willing to work around the clock through the weekend to speed up the passage of the bill," Smith said.