The resignation of Suffolk County Council’s former education spokeswoman Lisa Chambers from the authority has formally robbed the ruling Conservative group at Endeavour House of its majority.

Until Mrs Chambers’ departure the Conservatives held 38 of the 75 seats at the county council – a single seat majority.

The majority fell from three to one earlier this year after Brian Riley was removed from the Conservative group after he emigrated to America but decided to retain his seat on the authority.

When he does attend the county council now – and he is currently in the country and will be attending meetings – he sits as one of the four Independents on the opposition benches.

However when he was removed from the group earlier this year, he told leading Conservative councillors he would be unlikely to vote against them, certainly on major policy.

He said: “When I met the Conservative group leaders (earlier this year) I told them I wouldn’t be voting with Labour or the Liberals – or UKIP come to that.

“But I don’t think I’ll be going back into the group.”

Mr Riley is one of four Independents on the authority – but they are not a group.

Richard Kemp, from Long Melford, is part of the Liberal Democrat and Independent group and Trevor Beckwith, from the Bury St Edmunds Eastgate and Moreton Hall division, is part of the Green and Independent group.

David Nettleton, who represents Bury St Edmunds’ Tower division is, like Mr Riley, totally independent of any other councillors.

No date for the by-election has yet been set, but it is likely to held early next year – and there has been a concern among the Tory group that it will be a distraction during the budget process.

Mrs Chambers had a majority of 353 over UKIP in May 2013 – winning by 968 votes to 615 with Labour in third place. However UKIP did win other seats nearby, and the party is likely to fancy its chances in a by-election whenever it is held in the new year.