A former Conservative MP and others accused of cheating by placing bets on the date of last year’s general election face a wait of more than two years for their trials.

Craig Williams, who also served as a senior aide to the then prime minister, Rishi Sunak, appeared along with the 14 other defendants at Southwark crown court on Friday.

He did not indicate a plea. Twelve of the defendants gave indications at a hearing last month at Westminster magistrates court that they would plead not guilty.

The Southwark court will hear an application to dismiss the charges on 19 January next year.

The large number of defendants means two trials will be held, with the first scheduled for 6 September 2027, and the second for 3 January 2028.

Williams, who was the Tory MP for Montgomeryshire and Cardiff North, will be in the 2028 trial. He is charged with cheating at gambling and three counts of enabling or assisting others to cheat.

The charges come out of Operation Scott, which investigated alleged gambling by politicians and employees of the Conservative party before last year’s general election.

Prosecuting on behalf of the Gambling Commission, Sam Stein KC told a previous hearing: “Operation Scott was an investigation launched by the Gambling Commission into politicians and employees of the Conservative party, and a former police officer … who had placed bets on the date of the 2024 general election with the benefit of confidential or insider information as to when that date might be.

“The prosecution says that placing bets with inside information is a criminal offence, namely cheating.”

Other defendants include a former Conservative member of the Senedd, Russell George, 50, and Thomas James, 38, the suspended director of the Welsh Conservatives, both of whom have previously indicated not guilty pleas.

The defendants could face prison sentences of up to two years if convicted.

Williams served as parliamentary private secretary to Sunak between October 2022 and June 2024.