Chancellor George Osborne is today expected to trumpet that the region is on the brink of a devolution deal to create an Eastern Powerhouse - but there could yet be a town hall backlash from councillors unhappy an elected mayor is a key part of the bargain.

A number of grassroots politicians from across the region and the political divide have said they have not yet been fully consulted, with many raising concerns about the prospect of an elected mayor - believed to be at the heart of the proposal.

Mr Osborne is expected to use his budget today to make a devolution announcement for Norfolk, Suffolk and Cambridgeshire, excluding Cambridge city, which said it did not want to sign up for the current proposals - a deal which has still not been made public.

A deal has been discussed behind closed doors and, although council leaders and MPs, one of whom hailed the 'bold devolution deal' know the details, they have been sworn to secrecy ahead of today's budget announcement.

But, the deal still needs to be taken back to each council to be voted on - and councillors frustrated at their lack of involvement in a process carried out in private meetings may not give it an easy ride.

And the government has refused to state whether, if councils vote against accepting the deal, it would force a deal upon them against their wishes.

One councillor, who did not want to be named, said there had been a great deal of disquiet and hinted a rebellion was brewing.

They said: 'We were elected last May and this wasn't on the agenda. Our leaders are not running our councils. They are in London twice a week.

'The story has been sold that we have to be at the table. It is a 'forced marriage'. We have been told it has got to happen.'

Bernard Williamson, a Labour borough councillor in Great Yarmouth said he wished he knew the details of the plan.

He said: 'No-one has seen the actual deal. We have not seen the governance structure. My concern is we do not know the details about how it will work for local councils and local people.

'I am personally not in favour of elected mayors, but that is part of the deal. We may have someone flown in from elsewhere to take the role. How much executive power will they have?'

Mr Williamson said he did not feel local councillors were being asked for their view, 'It is not that type of consultation, it is being driven by the centre from the top.

Alan Mallett, Conservative councillor for Coltishall on Broadland District Council, said his leader Andrew Proctor had kept him in the loop about the meetings he had attended.

But, on an elected mayor, he said: 'I think it is a damn silly idea. I don't see what it is going to mean to anybody.'

Virginia Gay, Liberal Democrat North Norfolk District councillor for North Walsham said she was not sure what powers would be devolved, or how it would affect north Norfolk.

She added: 'I need to think about an elected mayor long and hard as there have been mixed reports from other areas.'

Keith Gilbert, Breckland councillor for 20 years and Watton town councillor for 30 years, said he wanted to see powers devolved, but said an elected mayor was a 'political gimmick'.

He said: 'What's the point of having all the other councillors if we have an elected mayor? I wonder if it is a way of reducing the importance of local councillors – that could be a consequence.' And the Green group at County Hall criticised the 'rushed, secretive plans'. Leader Richard Bearman said: 'These plans walk all over local people and take power away from districts and boroughs.'

See live budget reaction on our homepage from 12.30pm today.