A former Welsh Labour leadership hopeful has said he does not want to be in the same party as former Liverpool council deputy leader Derek Hatton.
Mr Hatton, who was expelled from Labour in the 1980s for belonging to the far-left faction Militant Tendency, has been readmitted to Labour.
Alun Davies, a former Welsh Government minister, said the party was "betraying its values".
It comes as seven MPs quit Labour in protest at Jeremy Corbyn's leadership.
In a press conference, Welsh Government Economy Minister Ken Skates said he was "not happy that Derek Hatton is back in the party" and is "disappointed that we have lost seven incredibly capable members of Parliament".
He revealed that he himself had once tried to resign from the party over the Iraq war, but was convinced to stay.
Mr Hatton was expelled from the Labour Party in 1986.
The expulsion came after the Militant-led city council set an illegal budget and sent out redundancy notices by taxi to thousands of council workers.
This is appalling. At a time when we should be rooted in our values we are betraying those same values. I do not want to be in the same party as this man. https://t.co/U84Co4vqXB— Alun Davies 🏴 (@AlunDaviesAM) February 19, 2019
Confirming to the BBC he had rejoined, he said it is "good to be back" and insisted he had "stayed absolutely solid for the Labour Party" for 34 years.
Alun Davies, in a tweet, said on Twitter: "This is appalling. At a time when we should be rooted in our values we are betraying those same values.
"I do not want to be in the same party as this man."
Following the comments he later clarified that he would be staying in Labour.
Mr Skates said: "I'm incredibly disappointed that we've lost seven of our colleagues in Westminster, but I'm equally disappointed that we've allowed back in somebody who just 30 years ago was using taxis to hand out redundancy notices."
But Mr Skates said "I always believe it is better to stay and fight for what you believe in.
"It wasn't long ago that I wrote my letter of resignation from the Labour Party. I sent it to the Labour party, and that was in protest at the war in Iraq."
He said the letter was intervened by another party member, who told him to remain and express his views "if you want to see change", and he decided to stay.
"The lesson of the 80s shows that its better to stay and fight in a broad church," he said.
Meanwhile former Welsh Government minister Leighton Andrews has said he will not vote Labour if the party helps make Brexit happen.
"I very much hope I won't have to do this, but if Labour enables Brexit then I won't be voting Labour at the next election. I'm very clear about that," he said.
He says Jeremy Corbyn should push for another referendum on leaving the EU, offering voters the choice of the prime minister's Brexit deal or the chance to remain in the EU.
In the Senedd on Tuesday, First Minister Mark Drakeford said he "welcomed" a letter from Mr Corbyn to Theresa May that set out Labour's conditions for supporting her on Brexit.
Sent earlier this month, the letter angered prominent Labour politicians because it failed to mention the possibility of holding a referendum.
But former Bridgend council leader Jeff Jones tweeted: "What's the fuss?
"One of the Militants I helped expel in the 1980s was allowed back in under Blair. Another is now chief executive of a large local authority."