Jo Swinson has welcomed outspoken anti-Brexit campaigner Steve Bray becoming a General Election candidate for the Liberal Democrats in Wales.
Mr Bray has become famous for appearing in the background of news broadcasts from outside Parliament holding placards opposing EU withdrawal.
Party leader Ms Swinson insisted he should not be seen as a joke candidate in the Cynon Valley seat.
Ms Swinson told the PA news agency: “Our candidates are chosen by local and national parties, so the constituency will have chosen Steve as a candidate.
“He is a Liberal Democrat member and he is a passionate campaigner.
“He has been well-known within the Remain cause more widely and I am sure he will bring that energy to the campaign here in Wales.”
Asked how she would respond to people who might view him as a joke candidate like Screaming Lord Sutch, Ms Swinson said: “I would respectfully say that I disagree and he is somebody who is true to his values and cares very deeply.
“I think we do want to have our politicians care about the issues that they are addressing. I think Steve is an example of somebody who very clearly does just that.”
Mr Bray, 50, has gained the nickname “Mr No Brexit” for his antics outside the Commons on College Green.
He said his plans to swap his “blue EU hat for a yellow one” come as a result of Ms Swinson’s pledge to stop Brexit.
In previous elections he said he had voted for Labour, the Liberal Democrats, and once for the Conservatives and he admitted he faced a challenge to take the seat from Labour.
He said: “Its a Labour stronghold. I hope to boost the (Lib Dem) vote in the area.
“As much as I hate to say it, another referendum would just leave divisions.
“If that’s what it takes, so be it, but I would rather they put a stop to it at Parliament and they revoke Article 50.”
Labour MP Ann Clwyd held the seat, winning with a majority of around 13,000 in 2017, but has decided not to run for election this year.