Nigel Farage’s keynote speech at the Reform Party conference was disrupted by hecklers and protesters following a security scare.

Several campaigners had to be thrown out of the main hall in Birmingham’s National Exhibition Centre while the Reform UK leader was on stage.

One had held up a banner in the centre of the auditorium that read: “Reform works for billionaires.”

At least four demonstrations took place during Mr Farage’s speech, in which he vowed to not to be “distracted” by “a highly co-ordinated campaign of attacks”.

He had been delayed in delivering his address by a security incident after climate change campaigners unravelled a banner on stage.

When he began his speech, an hour later than planned, two women hecklers were thrown out of the conference hall.

They were booed by audience members who shouted “out” before they were removed by security.

Mr Farage said: “We’ve got a screamer.”

Later, protesters were removed in separate incidents. Mr Farage joked that ticket prices could be raised next year to weed out campaigners against the party.

Mr Farage and his party are facing a police investigation over allegations they breached political donation rules.

Reform took funding from a “US firm” for three polls it commissioned earlier this year costing £32,500, Channel 4 News reported on Thursday night.

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

Foreign companies are not allowed to provide funding for UK parties, including for payments for studies and research, under electoral law.

The Clacton MP denied any wrongdoing, telling delegates: “Reform has broken no law. We take compliance extremely seriously.

“And ask yourself, why is all of this happening? Anyone got a clue why it’s happening? Because they’re scared of us. That’s why it’s happening.

“And in my case, I’ve broken no laws, abused no public money. I haven’t even got a motorhome, believe you me.

“I’m accused of non-declaration of a personal gift, a personal gift that might just keep me alive.

“But I couldn’t wait forever. I couldn’t wait for six months or a year for this committee to decide. So I said, ‘Right. I tell you what, the voters of Clacton, they can be my judge.’ And the people of Clacton have decided with an emphatic win.”

Reform UK deputy leader Richard Tice was also interrupted while addressing delegates ahead of Mr Farage’s speech.

Greenpeace claimed responsibility for a banner being unravelled on the stage.

Amy Cameron, programme director for Greenpeace UK, said: “Tice wants to celebrate this summer’s relentless heatwaves and droughts because they’re improving English sparkling wine.

“But the only thing being toasted in England is our farmland, and the only way you could miss that is if you’re paid not to notice.”

Security personnel and a search dog were gathered behind the stage where events in the main hall were paused ahead of Mr Farage’s speech.