The 'rainbow' alliance at Norfolk County Council has been thrown into doubt as the Green Party have threatened to withdraw support for Labour leader George Nobbs just days before he fights for re-election.

Mr Nobbs, who has been leader of the council since 2013, has done so with the support of the Liberal Democrats, UKIP and the Green Party.

Last May he won the support of 42 votes compared to Cliff Jordan, leader of the Conservative Group, on 39.

But the four Green county councillors have now written to Mr Nobbs, who represents the Crome ward, announcing they will abstain from the vote on Monday's council meeting.

Richard Bearman, leader of the Green group, said they would stand back from the vote as a result of Mr Nobbs' 'ardent support for constructing the Norwich NDR, and the shambles of the content of the devolution agreement'.

'Our objection is also to the content of the agreement,' he added. 'There is no mention at all of climate change, the biggest issue facing us this century.'

Clive Lewis, Labour MP for Norwich South, said handing the balance of power to the Conservatives in protest over devolution was 'not an acceptable reason' and issued a plea for them to support Mr Nobbs.

'I would ask them to listen to the better angels of their nature,' he said.

'If they abstain they will be handing over our county council to the Tories at a time when we have a Tory government making some of the most drastic cuts to local authority services we have ever seen.

'They would have to live with that decision, and when the cuts begin to bite people will know it could have been done differently.'

Cliff Jordan, leader of the Conservative group, said he will be contesting control of the council as usual.

'I don't agree with how George has run the alliance and that is no secret,' he said. 'We tried to take the council last year and will try to take it again this year, but we will do it in an open and honest way, so we will wait until the AGM when it is legitimate.'