Liberal Democrat MP John Leech has expressed disappointment that his bill to pardon gay mathematician and computer scientist Alan Turing has been delayed following opposition by a single Tory MP.

Mr Leech, the Lib Dem MP for South Manchester, proposed the pardon in the form of a private members’ bill. It has been co-sponsored in the House of Lords by the Lib Dem peer Lord Sharkey.

The bill passed its third reading in the Lords in October.

It seeks to give a statutory pardon to Turing who was prosecuted for “gross indecency” in 1952 after having a relationship with another man. He took his own life two years later.

Last Friday’s second reading of the bill in the Commons was delayed because of an objection by Tory MP Christopher Chope.

“I’m very disappointed that one solitary objection has delayed this bill,” Mr Leech said in a statement. “The persecution by the state for being gay is a scandal that shouldn’t be allowed to stand and it is only right that we are pushing for this posthumous pardon.

“Alan Turing was a Manchester hero and a national hero. He helped shorten the war and was then persecuted by the state for his sexuality. He should be pardoned and this would be a fitting way of saluting his memory. I will continue to push for a posthumous pardon for Alan Turing because I believe it is morally right.”

Second reading of the bill in the House of Commons will now take place on 28 February.

Earlier this autumn, former Tory chairman Lord Tebbit was criticised by Mr Leech after the peer warned pardoning Turing would set a “dangerous precedent”.