A UKIP AM has been recorded using a racial slur about an MP in a phone call to a former member of her staff.
North Wales AM Michelle Brown was recorded using derogatory comments about Labour MP for Streatham, Chuka Umunna, in a call in May 2016 to her then senior adviser Nigel Williams.
Ms Brown said her language was "inappropriate" and has apologised.
Mr Williams, who was her senior adviser for 12 months, was sacked by Ms Brown in May.
Ms Brown, who called Mr Umunna a "coconut", was also recorded using an abusive remark about Tristram Hunt, who was then Labour MP for Stoke-on-Trent Central.
In a statement, Ms Brown said: "The point I was making is that because of his considerable wealth and privilege, Chuka Umunna cannot possibly understand the difficulties and issues that the average black person faces in this country any more than I can, and I stand by that assertion.
"I do however accept that the language I used in the private conversation was inappropriate and I apologise to anyone that has been offended by it.
"As far as the language I used about Mr Hunt is concerned, it was a private conversation and I was using language that friends and colleagues often do when chatting to each other."
An assembly Labour Group spokesman said: "This is absolutely outrageous language and lays bare the disgusting racism at the heart of UKIP.
"Anything less than immediate suspension would be a clear endorsement of Michelle Brown's racist slur."
Ms Brown's comments have been referred to the assembly's standards commissioner.
Mr Williams said he believed Ms Brown should resign from her seat and UKIP's national executive committee should remove her from the party.
"You wouldn't expect anyone to say it, let alone somebody in such a position. It's appalling," he said.
"Michelle Brown is not fit for office saying things like that. UKIP HQ should do the right thing. The party does not want people with views like that in the party. End of."
UKIP AM David Rowlands said he "thought we'd put that racist language behind us as a party".
The regional AM for South Wales East said: "It's an inappropriate comment. It's certainly not the kind of language I'd use.
"I don't know if there's been any provocation but I'm very disappointed that anyone in my party should be using that language.
"However, it does puzzle me that someone can record and release a private call without the knowledge of the other person."
Plaid Cymru leader Leanne Wood said: "This racism reflects poorly on our parliament - The National Assembly for Wales - and that's why her party should take action on this.
"No to racism in all its forms. No tolerance on racism in our Assembly."
This is not the first controversy Ms Brown has faced - in February, she was forced to deny claims she had smoked "recreational drugs" in a Cardiff Bay hotel room.
Her spokesman said the smell was caused by the AM smoking a strong tobacco product.