Investment in the first new nuclear plant to be built in the UK in 20 years – at Hinkley Point – has secured final approval.

The decision came at a board meeting of French utility EDF – the company financing most of the £18bn project.

Following that agreement, legally binding contracts will be signed and construction work can begin.

But critics warn of environmental damage and potential escalating costs.

They are also concerned that the plant is being built by foreign governments. One third of the £18bn cost is being provided by Chinese investors.

EDF hopes to have more than 2,500 workers on site by next year.

Announcing the approval of investment, EDF described the plant as “a unique asset for French and British industries”, saying it would benefit the nuclear sectors in both countries and would give a boost to employment.

The announcement was immediately welcomed by employers’ group the CBI, the Nuclear Industry Association and engineering workers’ union GMB.

Somerset economy poised for boost

The final decision over building a new £18bn nuclear power plant at Hinkley Point in Somerset has been five years in the making. Now the EDF board has voted yes, thousands of firms in the West Country are hoping to reap the benefits.

So far £250m of contracts have been agreed with companies along the supply chain and plans for several hotels are already in the pipeline.

There are two main aspects to the project – building the nuclear power station itself and getting the infrastructure in place.

The new plant is expected to take between eight and 10 years to build and – at the peak of construction – up to 5,600 people will be working there, living in purpose-built hostels. These will be constructed in 2017, complete with football pitches and a gym.

They will go to work on a fleet of buses, many of which will be run by a Somerset coach company. About 650 workers are currently on site preparing for the major construction phase.

During the lifetime of the project, up to 25,000 jobs could be created, although not all of these will be at the same time.

Phil Adams, economic development manager at Sedgemoor District Council, said EDF’s decision would have an immediate “ripple effect” on the local economy.

He said: “It will be a catalytic project and new investment will come in pretty quickly.

“Many of these big contracts are sitting there just waiting to be signed.

“At present Somerset’s largest employment sectors are health and manufacturing, with the production of food and drink and tourism not far behind, but the construction phase will change all that.

“The potential of Hinkley C has been felt for a while and local businesses have been expanding their services and increasing their staff numbers in expectation of this decision for many months.”

EDF has been working with the Somerset Chamber of Commerce to prepare firms in the area for work on the plant.

The energy firm has held numerous meetings with hundreds of small firms, explaining what work is available, and what they need to do to win it.

The result is a unique database of 3,200 firms who have been declared “fit for nuclear”.

Nobody is guaranteed work, but when EDF’s main contractors are looking for specialist sub-contractors, they have been told to look first at this list.

It covers the full range, from high tech engineers, steel fabricators, groundworks, right through to small carpenters, electricians and even taxi drivers and hairdressers.

At the chamber, Chris Langdon has spent the past five years creating the supply chain database.

He hopes that, as well as creating jobs in the county during the construction, Hinkley will improve skills in engineering and construction.

He said: “The skill level will lift. The careers that will come out of this for young people at school today is a massive legacy for the project and for the local economy.”