Reform UK have partially boycotted the Senedd in protest against a ban on one of their politicians for claiming white people are being "replaced".

The party's Welsh leader, Helen Jenner, said Joe Martin's ban was because of "undue pressure" from governing party Plaid Cymru and was an "infringement on freedom of speech".

Martin had been told he would not be allowed to speak in the Senedd's chamber until he apologised for the remarks, which the parliament's Presiding Officer Huw Irranca-Davies called "unnecessarily provocative and deliberately offensive".

Reform UK leader Nigel Farage called the ruling "ridiculous and outrageous".

Reform members, who make up by far the Senedd's largest opposition party, withdrew from most of the day's proceedings but returned to vote in the parliament in the evening.

Jenner confirmed her party's boycott on the steps of the Senedd on Wednesday afternoon.

"It is now clear that the freedom of speech of one of our Senedd members is being curtailed, meaning his constituents are being silenced," she said.

"We stand behind Joe, and we will not attend today's plenary session in protest at his treatment.

"Every Reform MS [Member of the Senedd] will be in their Senedd office working hard for our constituents."

Martin said he would not apologise.

"My voters sent me to the Senedd to speak on their behalf," he said.

"I am being blocked from doing so, and now it's clear that I have fewer rights than the people who elected me.

"That cannot be the situation in a national parliament."

Asked by BBC Wales if he genuinely believed white people were being "replaced" in the UK, Martin said: "That's obviously a fact."

Aliya Mohammed, chief executive of the charity Race Equality First, said "the idea that white people are being 'replaced' is linked to a conspiracy theory that creates division and wrongly portrays people from minority ethnic backgrounds as a threat".

"Immigration can and should be debated, but language that fuels fear and hostility has no place in public discourse," she said.

"Being Welsh or British is not defined by race or skin colour.

"Wales belongs to all of us, and our diversity is one of our greatest strengths."

Posting on X, Farage said it was "ridiculous and outrageous that Reform's duly elected Member of the Senedd, Joe Martin, has been banned from speaking in the Welsh Parliament".

"Why is it only Reform that's targeted like this?" he asked.

Martin was also backed by the leader of right-wing party Restore Britain, Rupert Lowe.

He called for the Senedd to be "shut down" if it was "going to shut down legitimate debate around demographic security and immigration".

Martin's Caerdydd Penarth constituency includes some of Wales' most ethnically diverse communities.

On Tuesday Martin asked for a Welsh government statement on the "demographic replacement of white British people" during business questions, when Senedd members are free to raise issues they choose.

Business Minister Heledd Fychan immediately asked the presiding officer whether the remarks were within the Senedd's standing orders - a set of rules that govern conduct in the chamber.

Standing orders give the presiding officer discretion to decide if contributions to plenary sessions - meetings of the full Senedd - use "discriminatory or offensive language".

Delivering his ruling later, Irranca-Davies said: "Until I receive a clear indication that the member understands the boundaries of acceptable parliamentary conduct and apologises to the Siambr [chamber], we will not be calling him to speak."

Senedd officials confirmed an apology would have to be made in the chamber during a plenary session.

The ruling does not cover committees.

Martin is a member of the Senedd's Equality, Human Rights and Social Justice Committee.

Irranca-Davies pointed out it was not the first time he had rebuked Martin. In September, he said Martin had made offensive remarks about surgeons working in the Welsh NHS gender service.

Plaid Cymru Senedd member Carrie Harper called Reform's boycott a "pathetic tantrum" that was a "disgrace to democracy".

"They'd rather play gimmicks and chase headlines than be serious about Wales' future and doing the job they were elected to do on behalf of the people they represent," she said.

Welsh Labour leader Ken Skates said he was "astonished" that Reform had "chosen Remembrance Day of all days to pull a political stunt".

"They claim to be on the side of our armed forces, of our veterans, yet when they have the chance to speak up on behalf of this community, they bolt," he said.

"It is shameful, unpatriotic and disrespectful to the Armed Forces community."

In the 2021 census 93.8% of people in Wales identified as white, down from 95.6% a decade earlier, with the country's overall population growing by 1.4% to 3,107,500.

The proportion identifying as Asian, Asian Welsh or Asian British, the next highest group in the survey, rose from 2.3% to 2.9%.

Mixed or multiple ethnic groups rose from 1% to 1.6%, and those identifying as Black, Black Welsh, Black British, Caribbean or African rose from 0.6% to 0.9%.