Construction of Sizewell C – now a step closer following agreement yesterday for the financial investment for Hinkley Point C – would boost Suffolk's economy by £1bn over a decade, it was claimed last night.

According to business leaders, the massive project on the county's coast would bring a huge boost, not just in the 25,000 jobs it would create while being built, but in the knock-on impact for the supply chain involving business across the region.

After years of delay, an EDF board meeting in Paris last night voted by 10-7 to give the go ahead for the £18billion Hinkley Point power station (HPC) which will signal stage two of the consultation for the near nuclear twin reactor power station at Sizewell.

A company statement said: 'The HPC Project is a major element of the Group's CAP 2030 strategy. The two EPR reactors at Hinkley Point will strengthen EDF's presence in Britain, a country where its subsidiary EDF Energy already operates 15 nuclear reactors and is the largest electricity supplier by volume.'

An EDF spokesman said the conditions had been met to allow it to sign the contracts with the Government, its historic partner China General Nuclear Power Generation and the main suppliers of the project. The signing of the contracts is the next stage to the start of work on HPC.

Business and energy secretary Greg Clark said: 'The UK needs a reliable and secure energy supply and the Government believes that nuclear energy is an important part of the mix. The Government will now consider carefully all the component parts of this project and make its decision in the early autumn.'

Mr Clark will now take time to study the details of the board's approval. No signings will be held today and there are no plans for Mr Clark to visit Hinkley.

John Dugmore, chief executive of Suffolk Chamber of Commerce, said the Hinkley go-ahead was 'significant and positive news' for what might happen at Sizewell as 80pc of work packages related to building and running a power station were non-nuclear, offering plenty of opportunities for SMEs in Suffolk and for regional businesses.

'The building of a new nuclear power station would boost our economy both during construction and once it is up and running.'

'We have been working closely with EDF Energy through our local supply chain website to ensure that as many local businesses have a chance to pick up contracts as possible should Sizewell C get the go-ahead.'

Suffolk Coastal MP Therese Coffey said: 'This is great news for energy security in Britain and great news for Sizewell C here in Suffolk.'

'EDF can now work towards the stage two consultation process to ensure any concerns residents and others have are taken into account before the construction phase goes ahead. Sizewell C will provide skilled, high paid jobs in our local area and we must continue the work to take advantage of the opportunities that this historic project will provide.'

Simon Gray, chief executive of the East of England Energy Group, welcomed the Hinkley Point approval, saying: 'This really is very good news for the nation and the regional economy.

'Nuclear power is vital to a mixed energy economy – helping to plug the hole as coal-fired production drops to zero by 2025. Wind and solar power are not guaranteed all the time but nuclear is, and the UK arguably has the most rigorous safety regimes.'

Peter Aldous, MP for Waveney, said: 'Nuclear power along with renewables will keep the lights on and move the UK towards a low-carbon future. East Anglia has a key role to play and this decision will hopefully bring forward the start of construction of Sizewell C where it is important to ensure that the full economic benefits are secured for local people and communities.'