Council leaders will today submit their bid for a string of sites in Norfolk to receive the government flagship 'growth' status, but the precise locations are being kept secret.

Norfolk, along with Suffolk, was among areas invited to bid to become 'investment zones' - which the government says will supercharge economic growth.

Those zones - which have sparked opposition from conservationists, countryside charities and the Bishop of Norwich - would have planning rules loosened and tax incentives offered to encourage commercial and housing developments.

Norfolk County Council has had barely three weeks to draw up an expression of interest after the zones were announced during prime minister and South West Norfolk MP Liz Truss's mini-budget at the end of September.

The council has put together a list of potential sites to be included within a zone - and the bid must be with the government by noon today.

But council leaders are keeping tight-lipped about exactly what they are asking for, or where the sites would be.

There have previously been suggestions a zone should be created in the ‘Cambridge to Norwich Tech Corridor’, encompassing towns like Wymondham, Attleborough and Thetford.

However, there have also been calls for a zone in Great Yarmouth.

While the specifics remain under wraps, Graham Plant, deputy leader of Norfolk County Council, confirmed there could be more than one site covered by the zone.

He said: "There is not a limit on the number of sites Norfolk can put forward, but they will be evaluated individually.

"The precise number of zones will be dependent on a number of factors - geographic distribution, balance of housing and commercial deliverability.

"There is no guarantee, that if Norfolk were to be accepted as an investment zone, that all the sites initially put forward will move through to delivery, planning and, ultimately, implementation."

Mr Plant said Norfolk County Council, the New Anglia Local Enterprise Partnership and district councils have been discussing which sites could be put forward.

But the council is not making public which locations are in the bid, saying that must remain confidential at this stage.

However, Carl Smith, leader of Great Yarmouth Borough Council, confirmed he wanted two sites in the borough - which he said he could not name - to be included in the expression of interest.

John Fuller, leader of South Norfolk Council, has long extolled the virtues of the Cambridge to Norwich Tech Corridor.

He said: "Extending the Oxford to Cambridge arc to Norwich can only make us richer and focusing on the A11 corridor to Norfolk means opportunities for great jobs and financial security for our county and country in a difficult world."

The zones - and the potential impact on Norfolk's countryside - have caused deep controversy.

A coalition of local representatives from the RSPB, the National Trust and Norfolk Wildlife Trust accused ministers of launching an "an open attack on nature, putting Norfolk's landscape, people and prosperity in great peril".

The Bishop of Norwich, who criticised the plans as "an assault on nature", is also part of the coalition.

At a meeting of the county council this week, Eric Vardy, the council's cabinet member for the environment was asked by Liberal Democrat councillor Steffan Aquarone if he thought the Bishop was correct.

Mr Vardy replied: "No".

Steve Morphew, leader of the opposition Labour group at County Hall, said the public should be told which sites are being considered now.

He said: "I think this is a significant issue for Norfolk and the public deserves to be involved in selection of the sites. It shouldn't be done behind closed doors.

"We have heard of some significant concerns from the emerging environmental coalition about the loosening of planning rules and we have no idea what the balance of commercial and residential would be.

"It has been a ridiculously short period to get the expression of interest in and a rush job on something of this scale is bound to be flawed."

Elsewhere in the country, Oxfordshire County Council has declined to submit an expression of interest for a zone.

The Liberal Democrat-controlled council's leader Liz Leffman said: "The de-regularisation of planning controls and reductions in environmental protection, which appear to be a condition of any investment zone, are incompatible with our net zero carbon aspirations and our commitment to protect and enhance biodiversity and environmental quality."