Mr Bray, a rare coin dealer from Port Talbot, has become well-known in Westminster for bellowing "Stop Brexit" through a three-foot megaphone during news broadcasts on College Green.
Sporting a blue and yellow top hat and a UK flag, the activist has spent every day outside parliament protesting against Brexit since 2017.
However Mr Bray could soon be on the other side of the iron gates, as the Liberal Democrat leader Jo Swinson revealed he would contest Cynon Valley, in South Wales, for her party.
Ms Swinson insisted he should not be regarded as a joke candidate in the seat, which was held by Labour MP Ann Clwyd for 30 years before she announced her intention to stand down.
She said: "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 "Stop Brexit Man" for his antics outside the Commons.
In an interview with The Independent last month, he said he would only quit his protests when Brexit had been scrapped.
Asked if he was being rude by interrupting broadcasts, he said: "“These Brexiteers are talking nonsense without being challenged. “I correct that.”
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