Cardiff City's chairman Sam Hammam was criticised today for sending a letter to fans calling them to support the city's council leader Russell Goodway ahead of next month's local elections.
The Labour-led council has granted planning permission to the club to build a new stadium.
Mr Hammam, who made his name as chairman of Wimbledon FC's "crazy gang" during the 1980s, said Mr Goodway - and other councillors backing the stadium scheme - should be supported, although it makes no explicit mention of the June 10 poll.
The letter reads: "Councillor Goodway and his fellow members and officers have driven a hard bargain, these social and enabling works will cost a great deal of money, but above all they saw the opportunity and they have delivered.
"He has his detractors, those that would stop all development because of their negative petty politics but he has not folded under the pressure and the way is now clear for us to deliver, this is fair".
The letter later adds: "The Council have made it possible and I want you to know that, they have supported us and unreservedly we support them as you should to ensure that they can finish with us the fantastic project that we have all started here at Leckwith."
Mr Hammam told BBC Wales's Dragon's Eye programme: "He is a great man and this man, the people of Cardiff owe him an eternal thank you, an eternal gratitude for what this man is doing.
"Not just on this project, on many projects he is a great leader.
He added it was wrong for people to suggest he was urging fans to vote Labour simply because he admired the council's Labour leader.
"Russell Goodway is the leader. He is a Labour man. But there are other people in the council other than Labour.
"The people who support this project are the people who want to move Cardiff forward.
"And from whatever political party, they should be supporting.
"And Russell Goodway himself should be supported."
Conservative AM Jonathan Morgan told BBC Radio Wales's Good Morning Wales programme that he believed the intention of the letter was to get people to back the ruling party.
He said he could not imagine the letter going out without Mr Goodway knowing about it.
But he said of Mr Hammam: "I'm sure he hasn't done anything wrong. It doesn't say vote Labour, I don't think it even mentions June 10 as being the local government election date.
"But it's pretty clear what the intention of the letter is."
Jenny Randerson, the Liberal Democrat AM for Cardiff Central, told the programme: "The intention is clear, and it's a free country and he can do what he wants."
She added: "Personally, I have great support for him and for his football judgment but I really doubt his political judgment."