Two key Nigel Farage aides have stepped down pending a probe into an ‘illegal’ donation sting.

James Orr and Dan Jukes are standing aside from their jobs as head of policy and assistant to the leader while allegations are looked into.

The furore is threatening to overshadow Reform’s annual conference taking place in Birmingham, where Mr Farage is hoping to revive the party’s fortunes amid flagging polls. 

A report broadcast by Channel 4 News claimed Reform took funding from a US firm for three polls it commissioned earlier this year costing £32,500.

Senior Reform figures including leader Nigel Farage are said to have discussed a £500,000 donation from a US businessman through his son, who lives in the UK 

The purported donors were in fact undercover reporters from investigative group Verbatim posing as an American financier and his UK-based son.

Senior officials including Mr Farage are also said to have discussed a £500,000 donation from the fake businessman through his son. 

A Reform spokesman said: ‘Reform UK has launched an investigation following the broadcast of a Channel 4 News programme.

‘Both individuals involved have stepped down from their respective positions pending the outcome of the investigation.

‘The party believes it is important that the investigation is allowed to proceed independently and without prejudice. No further comment will be made while the investigation is ongoing.’

Reform UK chairman Lee Anderson told Sky News there was ‘no chance’ of them returning to the party. 

However, deputy leader Richard Tice refused to rule out a comeback, telling BBC Radio 4’s Today programme: ‘Let’s wait and see what the investigation says.’

Farage and his senior aide Dan Jukes were filmed meeting a US businessman and his son, who lives in the UK, and discussing donations. The men were both undercover members of Verbatim, a group of investigative journalists

Foreign political donations are banned in the UK. The donation was never made.

The Lib Dems have written to the Metropolitan Police and Electoral Commission about the issue. 

Labour has also reported the allegations to the police, and the Greens have called for a probe.

In a letter to the Met Police, Lib Dem Cabinet Office spokesman Lisa Smart wrote: ‘The breach raises alarming questions about whether there has been a wider complacency toward foreign interference by the individuals involved.’

Mr Anderson told Sky News of Mr Jukes and Mr Orr: ‘They’ve stepped down. They was told, you know, they had to step down, they have stepped down, and that’s got to be the right thing to do on the day, the first day of our conference.

‘Let’s remember, we’ve got 5,000 members coming through the door today to listen to what we’ve got to say about our first 100 days in government and how we’re going to change the course of this country.

‘So it’s right to get rid of this distraction straight away. The pair concerned have gone, and the investigation starts today. It’s as simple as that.’

He added: ‘There’s no chance of them coming back. They’ve stepped aside.

‘You know, we’re a serious party, you know, and sometimes in politics, you have to make tough decisions, harsh decisions.’

Mr Farage is expected to give the first of his two conference speeches on Friday afternoon, in which he will promise to declare a ‘national emergency’ on his first day in government, introducing a flood of legislation and doing ‘anything and everything’ to deliver his party’s policies.

He will say: ‘Within days of winning the general election, we will introduce dozens of Bills and force Parliament to sit all through summer for seven days a week to pass them.

‘Britain is in serious trouble. We don’t have time to wait around to fix it.’

The two-day conference in Birmingham is expected to hear from other senior Reform figures setting out their own pledges for their first 100 days in office, as well as an address from Jordan Bardella, leader of the French National Rally.

Mr Farage is expected to announce that any frontbenchers who fail to deliver on their pledges ‘will be sacked’.

He is also due to make his own promise to focus on reducing the cost of living and lead on efforts to end small boat crossings in the Channel.