Shadow chancellor John McDonnell has apologised for saying in 2003 that IRA members should be “honoured”.

The MP, appointed by new Labour leader Jeremy Corbyn, said the comments had clearly caused offence and apologised “from the bottom of my heart”.

Speaking on BBC Question Time, he said he had been trying to give both sides of the conflict a way to lay down arms with “some form of dignity”.

Unionist politicians welcomed the apology but questioned his motives.

Mr McDonnell also said he was sorry for an “appalling joke” about former Conservative Prime Minister Margaret Thatcher.

In 2010, he said that if he could go back in time he would “assassinate Thatcher”.

Challenged on this remark by a member of the audience, he said: “It was an appalling joke. It’s ended my career in stand-up, let’s put it that way, and I apologise for it as well.”

Mr McDonnell’s remarks about the “bravery” of the IRA have been highlighted since his appointment to Mr Corbyn’s shadow cabinet.

His remarks were made at a gathering in London in 2003 to commemorate IRA hunger striker Bobby Sands.

Mr McDonnell told the meeting: “It’s about time we started honouring those people involved in the armed struggle.

“It was the bombs and bullets and sacrifice made by the likes of Bobby Sands that brought Britain to the negotiating table.”

Speaking on Question Time on Thursday, he said at the time he made the comments it had looked like “we were going to lose the peace process”.