Cardiff Council's former Labour leader Russell Goodway has made an astonishing attack on Welsh First Minister Rhodri Morgan.
Russell Goodway says he won't be making an official complaint
Mr Goodway, who resigned as head of the Labour group after last week's elections, accused Mr Morgan of planning for him to lose his seat.
He alleged Mr Morgan wanted his independent opponent to win instead.
But the claims were dismissed as "outrageous" by a member of Mr Morgan's assembly government cabinet.
Assembly economic development minister Andrew Davies said the "real story" of the election was the state of the opposition parties, with Plaid Cymru in "turmoil".
On the Goodway allegations, Mr Davies said: "Russell Goodway's suggestion this morning that Rhodri conspired to oust him from Cardiff is outrageous.
"When political careers come to an end in a democracy, it is because the voters have decided it that way in the ballot box.
"It is very tempting to cast around for others to blame but that is not going to change the voters' verdict one iota.
"Every defeated political leader should always look in the mirror first, before thrashing around and pointing the finger of blame at somebody else."
Mr Morgan's office also said he refuted the allegations.
Mr Goodway's forthright style of politics meant he was regularly in the headlines during his twelve years at the top.
He kept his own seat in Thursday's vote, but Labour lost overall control in Cardiff and the Liberal Democrats became the biggest party.
Rhodri Morgan's constituency includes Russell Goodway's ward
Speaking on BBC Radio Wales, Mr Goodway denied the election was a referendum on his own popularity, but said the opposition parties and "my opponents in the Labour Party" wanted to make it one.
"I have to say that it was Rhodri Morgan's intention that I should lose that seat and he tried hard to make sure that I didn't get a chance to stand there in the first place," he told Good Morning Wales.
Asked if he was serious, Mr Goodway quoted a Western Mail report that senior Labour figures were frustrated that the Liberal Democrats didn't give the independents a free run in his Ely ward.
Mr Goodway went on: "But I also know what's been going on in the background for over 18 months now in trying to stop me standing in that seat".
He was asked what evidence he had that Mr Morgan would have preferred to see his independent opponent, Charlie Gale, winning his seat.
"I think you can see that it was people close to him back 18 months ago that tried to prevent me from being put on the panel of candidates," said Mr Goodway.
"I understand from sources that as much as six months ago before Charlie Gale made any announcement (that he would stand) that he (Mr Morgan) was saying to journalists in the assembly - and I've got it from someone who overheard a conversation - that he was predicting that Charlie Gale would stand.
"He was predicting that Greg Owens would take over as the leader of the Labour group immediately after the election. It seems that this was all part of some plan."
Asked if he would make a formal complaint against Mr Morgan, Mr Goodway said: "No - we've got other, more important things to do.