Workers made a fresh protest on Tuesday over the use of foreign labour.

Skilled but unemployed construction workers gathered outside the EON power station on the Isle of Grain to protest over the use of foreign labour in the UK.

A gas-fired plant is being built at the site by lead contractors Alstom but the trade union Unite, which has organised the demonstration, claims the company is using two sub-contractors who are refusing to consider local labour.

But the company insists its recruitment policy is fair.

A statement released by Unite says: "At the Isle of Grain, two sub-contractors have refused to consider applications for work from UK-based labour. Unite estimates that the two sub-contractors will require 450 workers over the lifetime of the project. Alstom has been contracted by E.ON to build the power station.

"Unite is calling on the government to insist that companies applying for contracts on public infrastructure projects, sign up to Corporate Social Responsibility agreements which commit to fair access for UK Labour."

Alstom says it has about 15 sub-contractors working at Grain, the overwhelming majority of which are British, with only two being non-UK companies.

A spokesman said: "We always give British firms and workers an equal chance to bid for work on the project. We do not and will not discriminate."

Derek Simpson, Unite's joint general secretary, said: “Unemployed construction workers are asking for fairness, not favours.

"UK-based labour must be given a fair chance to get a cut of the action to build a new generation of UK power stations."

The demonstration also calls for migrant construction workers to receive fair pay when working on projects in the UK.