Nigel Farage flew to the US last night to coach Donald Trump ahead of his next presidential debate with Hillary Clinton.

The former Ukip leader will give the Republican nominee tips on how to defeat Mrs Clinton ahead of their second meeting in eight days' time.

And Mr Farage – praised for his debating skills during the EU referendum campaign – will also offer help in the build-up to the final clash, which is on October 19.

Mr Farage has been brought in at the last minute after the first debate in New York earlier this week gave Democrat Mrs Clinton a boost in the polls. Republican advisers were said to have been frustrated by Mr Trump's performance and vowed to prepare him more rigorously.

Nigel Farage flew to the US last night to coach Donald Trump ahead of his next presidential debate with Hillary Clinton

Allies admitted they had pushed him to change his preparation and tactics, and sources said Mr Farage was expected to help with this. Mr Farage triumphed over Nick Clegg on a television debate on Europe in April 2014.

An instant poll found 69 per cent of viewers thought Mr Farage had won, as he lashed out at big business and wealthy landowners.

Then in June this year – in the days leading up to the EU referendum vote – then-prime minister David Cameron refused to debate with him, agreeing only to appear on the same programme.

Mr Farage, who quit as Ukip leader following the referendum, has been lining himself up for a position on Mr Trump's team for months, comparing his fight with the campaign for Brexit.

In August, Mr Trump introduced Mr Farage during a speech in Mississippi. At the rally, Mr Farage said: 'I wouldn't vote for Clinton if you paid me.' He urged Republicans to 'get your walking boots' on as he drummed up support.

Mr Trump's next debate will in St Louis, Missouri. US sources said he had not yet grasped that he needed to bring in voters who were not sold on his temperament, policy positions or readiness to be president.

Mr Farage, who quit as Ukip leader following the referendum, has been lining himself up for a position on Mr Trump's team for months

Campaign advisers intend to drill him on answers, facts and counterattacks, and coach him on how to attack Mrs Clinton on issues even if he is not asked about them. But whether he is open to practising meticulously is a major concern, according to the New York Times.

Although analysts from both parties and several focus groups declared Mrs Clinton the winner of the first debate, Mr Trump tried to claim the victory. He cited unscientific online surveys, and told his advisers that he believed he had done well in the first half-hour of the 90-minute event.