Mayor Winter announced he was to form a separate group with two of his closest allies only last week, with he and Labour councillors Stuart Exelby and Eva Hughes registering themselves as "the Labour group".

But at a full meeting of Doncaster Council yesterday, the Mayor said the trio were "withdrawing" plans for a separate group. He said Coun Hughes had returned to Labour and he and Coun Exelby would be independent.

During the meeting Mayor Winter announced that his cabinet would be just three-strong for now, with him at the helm, Coun Exelby as deputy and Coun Hughes the third member of the executive.

He then invited the leaders of all political groups on the council, of any political persuasion, to approach him to apply for positions on the cabinet.

The mayor said he was responding to two damning reports released by a Government watchdog last week which highlighted problems caused by political backbiting.

He added: "We have to deliver a less adversarial approach to politics in Doncaster. Don't get me wrong, we should be happy to debate, but when arguments begin to impact on our services there is something seriously wrong.

"I offer today to the leader of the Conservative group, the Liberal Democrats and the Labour group to take up positions on a cross-party cabinet. I am equally keen to talk to any independent member of the council if they wish to participate."

Before Mayor Winter spoke, the council's new managing director Paul Hart appealed for calm and drew members' attention to the critical Audit Commission reports of last week, one of which centred on the treatment of his predecessor Susan Law.

Mr Hart said: "Now is the time for us to be measured and calm. The citizens of Doncaster should be reassured that we are delivering services and have some excellent staff. Members of the council should now work together."

However, just minutes after Mr Hart made his appeal a new political row broke out over the allocation of positions on council committees, with members of two opposition groups claiming they were being "excluded".

The council is currently made up of 27 Labour members, 15 independents, 12 Lib Dems and nine Conservatives. But for the last three years, all senior committee positions have been filled by members of the Labour and Tory groups.

Because of this the Lib Dems tabled a motion asking for proportional representation when selecting chairmen and vice-chairmen of committees, but it was voted down.

Coun Garth Oxby, leader of the authority's Alliance of Independent Members, distanced himself from new independents Martin Winter and Stuart Exelby and said the Tory and Labour members had kept the top jobs to themselves in a "stitch-up".