Premier Kathleen Wynne will take the witness stand in Sudbury on September 13, during the upcoming Election Act bribery trial.
On Wednesday, Wynne told reporters she will testify in one week's time.
The premier will appear as a Crown witness in the trial, where two high profile Liberals are facing Election Act charges.
The trial for Pat Sorbara, the premier's former deputy chief of staff, and Sudbury-based Liberal fundraiser Gerry Lougheed Jr., is set to begin on Thursday.
Sorbara faces two bribery charges under the Election Act. Lougheed faces one charge.
The pair is accused of offering a would-be candidate, Andrew Olivier, a job or appointment to get him to step aside in a 2015 byelection for Wynne's preferred candidate, Glenn Thibeault.
At the time, Thibeault was a New Democrat MP. He is now the energy minister.
Though Wynne is being called as a witness by the Crown, she has said that she had already decided Olivier would not be the byelection candidate and as a result there was no need to offer him anything in exchange for not running.
Sorbara and Lougheed both deny the charges.
Lougheed had been charged criminally, with one count of counselling an offence not committed and one count of unlawfully influencing or negotiating appointments, but those charges were stayed last year.
The investigation was sparked by recordings made by Olivier, who was the Liberal candidate in Sudbury during the 2014 general election. As a quadriplegic man who often records his conversations in lieu of taking notes, Olivier recorded chats he had with Sorbara and Lougheed. Technical difficulties prevented him from recording a call he had with Wynne herself.
The bribery section of the Election Act says no person shall directly or indirectly "give, procure or promise or agree to procure an office or employment to induce a person to become a candidate, refrain from becoming a candidate or withdraw his or her candidacy."
A conviction under the bribery section of the Election Act carries a penalty of up to $5,000. If a judge finds it was broken "knowingly," the penalty is a fine of up to $25,000 and/or up to two years less a day in jail.
Here are some key dates in the scandal:
Nov. 20, 2014: Sudbury New Democrat MPP Joe Cimino resigns after just five months on the job, citing "personal health wellness."
Nov. 30: Premier Kathleen Wynne meets with NDP MP Glenn Thibeault, who agrees to run for the provincial Liberals. Wynne has said she decided at that meeting to appoint him.
Dec. 11: Local Liberal and chair of the Sudbury police services board Gerry Lougheed visits Andrew Olivier, the failed Liberal candidate in the June provincial election who was seeking to run again. Lougheed asks Olivier to consider stepping aside and nominating Thibeault and tells Olivier "in the course of that deliberation" to consider "appointments, jobs, whatever."
Dec. 11: Wynne phones Olivier, who is quadriplegic and tapes conversations as his way of taking notes. He says technical difficulties prevent him from recording that exchange.
Dec. 12: Pat Sorbara, Wynne's deputy chief of staff, phones Olivier and says Wynne is "going to have to make a decision around the appointment," later telling him they should chat about what he would be interested in doing, be it "appointments to boards or commissions," a constituency office job or role in the party executive.
Dec. 15: Olivier goes public with claims that Lougheed and Sorbara offered him a job or appointment to step aside. Opposition parties ask the police and Elections Ontario to investigate.
Dec. 16: Thibeault publicly announces he will be the Ontario Liberals' byelection candidate.
Jan. 12: Ontario Provincial Police conclude no criminal offence was committed by the Liberals.
Jan. 15: Olivier releases audio of his conversations with Lougheed and Sorbara; Progressive Conservatives ask OPP to reopen the investigation.
Feb. 5: Thibeault wins Sudbury byelection.
Feb. 19: Elections Ontario makes "unprecedented finding" that Lougheed and Sorbara's actions were in "apparent contravention" of the Election Act; matter is referred to OPP and federal Crown.
April 29: Wynne is interviewed by the OPP.
Sept. 24: Criminal charges of counselling an offence not committed and unlawfully influencing or negotiating appointments are laid against Lougheed.
April 27, 2016: Lougheed's criminal charges are stayed, OPP turn focus to Election Act investigation.
June 13: Thibeault is promoted from backbencher to energy minister as part of a large cabinet shuffle.
Oct. 3: Sorbara takes a leave of absence from her deputy chief of staff job to become the Ontario Liberal Party's CEO and 2018 campaign director.
Nov. 1: Sorbara is charged with two bribery counts under the Election Act, Lougheed is charged with one. Sorbara resigns her Liberal party posts.
July 25, 2017: Wynne says she will waive parliamentary privilege to testify in the trial. Thibeault later adds he will too.
Sept. 7: The trial is set to begin and last six weeks.
Sept. 13: Wynne is set to testify.
with files from The Canadian Press
