A project attempting to slash household bills is believed to have withheld almost £60,000 from energy companies.

Norwich City Council says around 20pc of the 1,768 properties that registered for its Big Switch and Save scheme accepted an offer to reduce their energy bills.

It is also believed others who did not switch were able to use the project to negotiate better deals.

But figures also show around 602 people, or 33pc, who were made an offer after the auction did not receive a cheaper deal.

The project aims to negotiate with energy companies on behalf of a large number of people, in an attempt to secure the best price.

Richard Wilson, environmental strategy manager, said: 'There was a saving of around £160 to 360 people, which is just under £60,000 that has remained in our economy.

'As a first tranche, lessons have been learned about how we market the scheme but it has been relatively successful for the numbers we expected for the first time. At the moment I am aware King's Lynn, North Norfolk and Breckland would like to have a scheme very similar to Norwich.'

Mr Wilson also confirmed that the council had secured £26,000 from the Department of Energy and Climate Change.

He said this will be spent on marketing the second attempt to encourage people to join the switch and save project.

This is to start at the end of January or beginning of February and will run for nine weeks – four weeks longer. Mr Wilson said around 5pc of the sign-ups in the first phase were by people who did not use a computer.

Councillor Keith Driver questioned at a committee meeting yesterday how the council will help people in deprived areas of the city who do not have access to the internet, but are likely to benefit the most from switching.

Mr Wilson said resources were limited so he had had to 'constrain ambition' during the first attempt. But he said this is an issue they are hoping to improve.

Green Party councillor Lucy Galvin has also previously questioned whether people who signed up to switch and save received the best deal possible, with internet searches suggesting cheaper or similar prices could be found with ease.

Bert Bremner, cabinet member for environmental strategy, said the project aimed to find people a 'competitive' fixed-rate deal for 12 months, while also preventing people having to search for tariffs.