Former Tory MP Imran Ahmad Khan is expected to cease being an MP three weeks after being convicted of sexually assaulting a boy following a delay in his resignation.

The Treasury is understood to have received his resignation letter and it is expected that he will officially leave Parliament on Tuesday, meaning he will receive full pay for April.

Khan said he sent the letter triggering the process on Monday, despite having announced his resignation on April 14 while coming under pressure to stand down.

He said he expects the process to finish on Saturday, but it was understood it would not happen until the next working day, with Monday being a bank holiday.

The Wakefield MP was found guilty of sexually assaulting the 15-year-old at Southwark Crown Court on April 11.

There were suggestions that a proper process needed to be followed before he could resign.

But parliamentary officials stressed that an MP can resign at any moment and pointed towards the case of Owen Paterson.

The Conservative announced his resignation from the “cruel world of politics” on November 4 after being embroiled in a lobbying scandal and an attempt to ward off his suspension.

The next morning, the Treasury announced he had been formally stood down from the seat of North Shropshire by being appointed to the Steward and Bailiff of the Manor of Northstead, one of the archaic means of resigning MPs.

Khan was expected to be appointed to the Chiltern Hundreds.

The disgraced politician had been resisting calls to resign until conceding it would be it “intolerable” for voters in the West Yorkshire constituency to have muted representation while he appeals the conviction.

He said the move would allow him to “focus entirely on clearing my name”.

After his departure is confirmed, it will set up a challenging by-election for both Prime Minister Boris Johnson and Labour leader Sir Keir Starmer.

Wakefield was one of the traditional Labour heartlands seats seized by the Tories in the 2019 general election.

Mr Johnson will battle to retain the constituency after facing months of bruising allegations centring on Covid law-breaking parties in Downing Street and after he was personally fined.

But Sir Keir will feel pressure to win back the seat that had been Labour since the 1930s as he tries to prove to voters the party has transformed since he took over from Jeremy Corbyn.