John McDonnell, controversially appointed as Shadow Chancellor of the British Labour Party by Jeremy Corbyn this week, has apologised for saying IRA members should be "honoured".

Confronted on TV, the left-wing Labour MP said his comments, made in 2003, had clearly caused offence and he apologised "from the bottom of my heart".

The new Shadow Chancellor, who has been under fire since his appointment over previously speaking about the "bravery" of the IRA, said he had been urging militants to "put their weapons away".

Speaking on BBC TV's Question Time, 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".

Mr McDonnell was challenged on his Thatcher remark by a member of the audience and 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."

Attempting to explain his previous comments about the IRA, made at a gathering in London to commemorate IRA hunger striker Bobby Sands, he said at the time he made them it had looked like "we were going to lose the peace process".

He now says his choice of words was wrong, adding: "What I tried to do for both sides is to give them a way out with some form of dignity otherwise they wouldn't lay their arms down."

He said: "And can I just say this, because this has been raised with me time and time again - I accept it was a mistake to use those words, but actually if it contributed towards saving one life, or preventing someone else being maimed it was worth doing, because we did hold on to the peace process.

"There was a real risk of the republican movement splitting and some of them continuing the armed process. If I gave offence, and I clearly have, from the bottom of my heart I apologise, I apologise."

Mr McDonnell was also asked about Labour's policy plans after apparent differences between Mr Corbyn and some members of his Shadow Cabinet.

He said Labour backed a return of the 50p income tax rate, saying this would be debated within the party, but was not advocating pulling out of NATO.

In Prime Minister’s Questions on Wednesday, responding to DUP leader Nigel Dodds, David Cameron said people who seek to justify IRA terrorism "should be ashamed of themselves".