The multi-million-pound purchase of a former Aviva office to house two Norfolk councils has been approved by one authority - despite a range of opposition concerns.

Broadland and South Norfolk have been in discussion to purchase the Horizon Centre at Broadland Business Park, to bring their joint staff together into one building.

On Thursday, Broadland became the first of two councils to approve the purchase.

However, a series of fears were raised by opposition councillors about the suitability of the site, whether all the options have been fully considered and whether information is being kept out of the public eye.

If South Norfolk Council does not approve the purchase on Monday, Broadland has agreed to go it alone and purchase the property.

Buying it would cost an estimated £10.1m, partially offset by the £5.2m sale of the councils' current headquarters in Long Stratton and Thorpe St Andrew.

Recommending the sale, councillor Jonathan Emsell, portfolio holder for transformation and organisational development, said the building would help Broadland lead the way in Norfolk by reducing its carbon emissions.

He said: “We now have an opportunity to further the financial savings made by our collaboration project to house our One Team in one building, saving running costs of two sites, will reduce our carbon footprint by over 80pc, with further improvements possible."

Dan Roper, a Liberal Democrat councillor, said he was not against bringing together councils’ staff into one building but criticised the lack of consideration for using their current building, Thorpe Lodge, which he said could save millions.

He said: “We are rolling over and letting south Norfolk tickle our tummy on this one because they are saying the only way this is going to happen is if we move to a new building not come to Thorpe Lodge.”

Steve Riley, chairman of the scrutiny committee, said the council was rushing into buying an oversized building, with large unusable areas that will require heating.

Conservative John Fisher rejected the Lib Dem suggestions Thorpe Lodge could be made more energy-efficient and that it would not be able to support the number of solar panels needed to power it.

Councillors were forbidden from discussing several issues in public, including a noise report, and energy reduction feasibility and accessibility studies.

Despite a challenge from this paper, the council's monitoring officer said it was confidential information.

The law used by the council should only apply to the financial information or business affairs of third parties.

The purchase was approved 23 for and 11 against.