Ambitious �25m plans to transform two of Norwich's most historic buildings into a concert hall and conference centre have been put on ice for at least four years.

Hopes that St Andrew's Hall and Blackfriars' Hall could be turned into a regionally important cultural and conference venue have been dashed for now - because tough economic times have made raising the money needed impossible.

Norwich Heritage Economic and Regeneration Trust (HEART) has been working on the project, which they said would give the city a �170m economic boost, since 2008.

Almost half a million pounds has already been spent on the scheme, though council bosses insist that will not be wasted.

They wanted to breathe new life into the halls by making it fit to host concerts with soundproofing and a conference centre.

It had been hoped that would make the halls, which have a net revenue of about �300,000 a year at the moment, self-sustainable.

But a bid to the National Lottery for �7.5m funding failed and Norwich City Council, which owns the buildings and has been working in partnership with HEART, says there is no way it can provide funding in the current financial climate. City Hall was told this week that its spending power will be reduced by 8.9pc in each of the next two years, which means the council will have to find extra savings this year on top of the �3m it had already identified.

That means it can no longer give any money towards the halls project.

The halls currently hold about 800 people, but it had been hoped that, following the renovations, the capacity would rise to more than 1,000.

Alan Waters, cabinet member for resources, performance and shared services, said: 'In these tough financial times our first priority has to be protecting front line services.

'An awful lot of hard work has gone into The Halls project to this point and we would like to thank all those involved. 'I must stress that this work will not be lost, and when the time is right for us to pick up this project again we will do so.

'For the time being the message is that The Halls are very much open for business as usual. The council will continue to manage them for the good of the city.'

The regeneration scheme has cost just under �500,000 up to now, with investment from HEART, the East of England Development Agency, Noriwch City Council, Norfolk County Council and the Greater Norwich Development Partnership.

In 2008 HEART canvassed public opinion and found an almost unanimous feeling that improvements were needed to the buildings' toilets, bar and foyer areas, acoustics, appearances and access.

Heritage bosses, who had been working with Hopkins Architects on the project, were disappointed at the blow, but said they hoped to resurrect the proposals in the future.

Michael Loveday, chief executive of Norwich HEART said: 'Over the last four years, HEART has deployed funding from a range of sources to take forward The Halls project, and it now represents a well-developed scheme exploiting the skills of some of the top professionals who have a track record of achievement with similar challenges elsewhere.

'We are disappointed that further progress has for the time being been halted because of financial constraints. If and when circumstances change, HEART is ready to take up the challenge once more.'

It had been hoped the work could start next year, with the revamped halls opening in 2013.

St Andrew's Hall has had a troubled time in recent years. In 2006 magistrates criticised the management of the historic hall after an appeal was launched by neighbours against licensing at the venue.

Magistrates were critical of the city council for not knowing about the conditions of the hall's public entertainment licence, not investigating complaints properly and managing the venue poorly.

The magistrates' decision led to the cancellation of a number of events at the hall while the its managers were ordered to operate a noise limiter and stop amplified music after 10.30pm - an hour earlier than had been in place.

• What do you think of the decision to put the scheme on ice? Write to Evening News Letters, Prospect House, Norwich, Norfolk NR2 3LD or email eveningnewsletters@archant.co.uk