A "ground-breaking" agreement on pay and conditions will benefit thousands of workers set to build a new nuclear power plant.
The GMB, Ucatt and Unite unions said 5,000 workers at the EDF site in Hinkley Point, Somerset, will be "directly employed, well rewarded, and treated with respect and dignity" under the deal after months of negotiations, which will see wage rates increase to at least £13 an hour.
The French company is yet to start construction work on the site as protracted negotiations continue with the government over the so-called strike price for electricity produced from the new power station.
The project will be the largest single building site in Britain, with 5,000 workers employed at the peak of construction.
The Civil Engineering Sector Agreement establishes pay rates for the workforce which unions said are "significantly" above current rates of around £10.80 an hour. The agreement sets out provision for bonus and productivity schemes, as well as pension payments.
By January 2017, workers will see an amount equal to 10 per cent of their pay being placed in their pensions, through 5 per cent matched funding from employees and employers.
Phil Whitehurst of the GMB said: "In an important step to combat casualisation and poor productivity, the site will only directly employ workers through PAYE.
"For the first time in such an agreement, there will also be strict rules placed on the recruitment of workers through employment agencies. A top-of-the-range occupational health scheme will be established to help ensure the short-term and long-term health of the construction workforce.
"The agreement also makes clear that the training of traditional apprenticeships and adult trainees will be a priority. A target of training at least 500 apprentices and adult trainees during the lifetime of the project has been set."
Construction of Hinkley Point C could create jobs for around 25,000 people during construction, including around 5,600 people working on-site at the busiest time, said EDF.
About 400 apprentices would be trained during the project and 900 permanent jobs created in the planned power station.
Steve Murphy, general secretary of Ucatt, said: "This ground-breaking agreement will ensure that workers building Hinkley Point will receive excellent rates of pay and first-class conditions. This agreement will act as the blueprint for all future major construction projects."
Kevin Coyne of Unite said: "A new nuclear power station at Hinkley Point will be a significant milestone towards meeting Britain's low-carbon energy needs. We're pleased that progress towards a greener future is also characterised by good pay and conditions for thousands of highly-skilled workers.
"The unions and employers have made real progress in laying the right foundations for this important project. It is now time for the government to stop delaying and give EDF the certainty it needs so the company can get on with the job of meeting the UK's energy needs."
Hinkley Point C construction director Nigel Cann said: "These are important agreements for the project and having them in place now is a significant achievement. This reflects the strength of relationships between the parties involved and their commitment to make the Hinkley Point C project a success.
"The agreements will help set high standards for health, safety, skills and delivery. If it goes ahead, Hinkley Point C has the potential to provide a huge boost to UK industry and provide the country with the secure low-carbon power it needs for the future."
A statement from EDF added: "Negotiations between EDF Energy and the UK government on a contract for difference which would set the price for electricity produced by Hinkley Point C are continuing and both sides have characterised them as positive."