Nigel Farage has called for Theresa May to be sacked as Prime Minister and claimed plans for Brexit have become so "ludicrous" that Britain is going to be worse off than before the referendum.
The former Ukip leader and key member of the Leave campaign also said that if Brexit wasn't sorted out he'd consider a return to politics.
Mr Farage was speaking to ITV News Political Editor Robert Peston for his new online series, Now What?
On whether the Conservative Party should get rid of May, Mr Farage said: "Absolutely, of course, she's a disaster. She's boxed herself into a position now where we will be, for the foreseeable future after March [29th 2019, Brexit day], actually in a worse position than we were before we voted to leave. It’s ludicrous.”
Asked by Peston to clarify whether he thought this "half in, half out" position "is worse than being in the EU", Farage replied "of course".
Watch the full episode of Now What? with Nigel Farage here
Pushed about why he didn't work with government to deliver a roadmap for Brexit, Mr Farage added: "They wouldn't use me, they wouldn't talk to me.
"Whatever I put forward, they wouldn't listen to me anyway. I'm still there making arguments and I will go on making those arguments."
And on the prospect of Brexit failing he added: "I’m enjoying my life much more than I was leading that party. They were fun at the time, but I’m pleased it came to an end.
“I did it at a fanatical level, I did the best I could, I didn’t do badly. I don’t want that life again.
“If I see Article 50 being delayed or being stopped, I will then have no choice but to throw myself back in the front line of political campaigning. I hope it doesn't happen, but it may.”
His comments come after a turbulent week in Parliament for the PM.
On Wednesday she witnessed the SNPs Westminster leader Ian Blackford lead a walk-out of his MPs during Prime Minister's Questions over the Government's handling of the Brexit bill.
She was also forced to appoint a replacement for justice minister Phillip Lee, who quit her administration in order to be able to vote against the Government on Brexit.
Edward Argar was appointed Parliamentary Under-Secretary of State at the Ministry of Justice.
Mr Farage was also asked about extremist elements in Ukip.
"What I tried to do with Ukip was to make sure we did not have extremists within the organisation. I banned anybody who had ever been a BNP member from joining the party. I tried to make sure we could make the argument but without being tainted with the extremes.
I would advise Ukip to not become a party that campaigns on religion and do not become a party that gives a back door in to some very extreme elements."
Asked about the petition calling for the release of English Defence League co-founder Tommy Robinson from prison, which has received more than 600,000 signatures, Mr Farage said: "It tells us that people are getting quite scared. They're getting scared of what's happening in many of their communities, they're getting scared about division and their lives are being fundamentally changed by bad Government policy, state sponsored multiculturalism."
Mr Robinson was jailed for 13 months in May for contempt of court after broadcasting a Facebook live video from Leeds Crown Court about a trial.
More about our new online series Now What?
Hosted by ITV News Political Editor Robert Peston, Now What? is a series of interviews with figures from politics, business and beyond, exploring the big challenges facing the UK and the world.