Nigel Farage today declared Keir Starmer will be 'gone before the end of May' as the Peter Mandelson scandal has left the Prime Minister's credibility 'shot to pieces'.

The Reform UK leader accused Sir Keir of 'riding roughshod over normal procedure' in his appointment of the disgraced peer as Britain's US ambassador.

The PM is facing growing calls to quit - including from among Labour MPs - after the bombshell revelation that Lord Mandelson was given the senior role despite failing security vetting checks.

In a speech in Barnsley on Wednesday, as he continued his campaigning ahead of local elections, Mr Farage predicted Sir Keir would 'cling on' until next month's contests.

But the Reform leader said Labour MPs would 'move against' the PM after the 7 May elections, which - Mr Farage predicted - would see their party 'obliterated' in some parts of the country.

Mr Farage said his campaigning over the past few weeks had shown Labour is 'crumbling in its heartlands' as voters turn against the Government's Net Zero agenda and the 'unpatriotic' PM.

He suggested Reform would win more than a thousand council seats across England on 7 May, while also vying with Plaid Cymru to win the Welsh Senedd elections.

Mr Farage said a 'remarkable' result might also see his party come second - and ahead of Labour - in contests for the Scottish Parliament.

Earlier on Wednesday, Sir Keir did not deny during Prime Minister's Questions that Downing Street had also considered giving Matthew Doyle, his former spin doctor, a top diplomatic job.

Lord Doyle had the Labour whip withdrawn earlier this year after it emerged he had campaigned on behalf of a friend who had been charged with possessing indecent images of children.

'I think his credibility is shot to pieces,' Mr Farage said of Sir Keir at the rally in South Yorkshire.

'His actions and his judgement are seriously in doubt. I think if Labour get obliterated in the Red Wall, in South Wales and in Scotland then he'll be gone by the end of May.'

The Reform leader described Sir Keir as a man who has previously 'prided himself on being professional, on being thorough and good at everything he does'.

He added: 'The man of process has ridden roughshod over normal procedure.

'The very thought that Mandelson was even chosen in the first place is quite extraordinary, but the fact that he was actually put into a very senior position and open to confidential documents.

'Bear in mind that we share with the Americans intelligence to the highest level, including nuclear capability.

'The thought that the PM wanted this guy to be there on Pennsylvania Avenue without any vetting process having been done is astonishing.'

Sir Keir last week sacked Olly Robbins as the top official at the Foreign Office for not disclosing to him that Lord Mandelson failed security vetting checks.

The PM has previously seen Morgan McSweeney depart as his chief of staff over the damaging scandal, while he axed Chris Wormald as the head of the civil service in February as he scrambles to get his premiership back on track.

Mr Farage continued: 'My feeling is he (Sir Keir) will cling on. He'll sack everybody around him, even if he's the last man standing. He'll never, ever take responsibility himself for anything that he's done.

'So he'll hang on until 7 May. And on 7 May things are going to change...  we're going to show that if you vote Reform, you will get rid of Starmer.'