Nigel Farage says UKIP is "100% united" ahead of its EU referendum battle after two senior figures left their roles in the party.

Patrick O'Flynn has quit as economics spokesman after a personal attack on the leader, while Suzanne Evans is no longer head of policy.

Mr Farage said Ms Evans' contract had expired and he had "other plans" for her role within the party.

"One or two regrettable things" had been said by party figures, he said.

He added that the comments had been made by a small number of people since the election "pressure cooker" atmosphere.

'Big myth'

BBC assistant political editor Norman Smith said some UKIP figures privately thought Mr Farage lacked the broader appeal to lead the party during the referendum campaign.

"The departures would also seem to deprive the party of two of its most effective spokesmen, whose quieter manner was thought to have widened UKIP's appeal," he added.

The UKIP leader also hit back at back at the Confederation of British Industry - which has spoken out against a vote to leave the EU in the referendum promised by 2017 - saying the organisation had previously argued to join the Euro.

"They were wrong about that and I think they are wrong about this," he said, adding that it was a "really big myth" that the UK could not trade with the EU if it exited the union.

Analysis, by BBC political correspondent Robin Brant

Image copyright EPA

Just under two weeks ago, Suzanne Evans had been anointed interim leader of UKIP.

Yesterday she was unceremoniously told that her contract to lead policy development at the party was not being renewed.

I understand she wasn't informed beforehand by Nigel Farage. Now she has to wait until Friday to see what new role he wants to offer her.

Ms Evans spoke out in support of her election campaign press conference partner and now-former economic spokesman Patrick O'Flynn, after he attacked the UKIP leader - saying Mr O'Flynn was brave.

She has since denied being part of any plot to depose Mr Farage, saying the only person who was plotting against him was himself.

There was a defiant tone from her after she was stripped of the policy role. "I'm not concerned that my contract isn't being renewed," she told me. "The manifesto was a huge success and I'm not sure I could top it. Better to go out on a high, don't you think?"

The big question now is what will the leader offer the woman who was widely praised for her role in an election campaign, so much so that it ended with Mr Farage choosing her to take over (briefly).

Speaking on BBC Radio 4's Today programme, he said Prime Minister David Cameron's bid to renegotiate powers before the referendum would be an "attempted great stitch up" with "cosmetic" changes presented.

"Mr Cameron cries victory and on the basis of that we are suppose to support him in the referendum," he predicted.

Mr O'Flynn, an MEP for the East of England, apologised to Mr Farage for calling him "snarling, thin-skinned and aggressive".

'No purge'

Mr Farage said Ms Evans, who has confirmed she is no longer the party's policy chief, was "potentially a great electoral asset".

"There's no question that she is a very able woman." he said, but would not comment on whether she was a potential leader.

Ms Evans told the BBC's Victoria Derbyshire programme there had been "no purge" of party figures.

"When I last looked, Douglas Carswell is still an MP for UKIP, Patrick O'Flynn is still a UKIP MEP, and I'm still UKIP deputy chairman," she said.

"Now I don't know what parallel universe journalists live in, whereby a contract coming to an end can be deemed a sacking, but that's certainly not how I see it."

'Hint of nervousness'

In the European Parliament, some EU politicians referred to Mr Farage's resignation as party leader - which was subsequently reversed - during a debate on migration.

Guy Verhofstadt, the ALDE group leader, said: "Nigel Farage has sent a letter to Nigel Farage saying 'I resign', and Nigel Farage has responded to Nigel Farage saying 'I refuse'".

EPP group leader Manfred Weber told Mr Farage: "You said you'd resign, and yet you are still here. You broke all your promises."

Responding, the UKIP leader said there was a "hint of nervousness" among his European colleagues, saying the UK's referendum would trigger a "fundamental debate on the existence of this union and the need for it in the modern world".