Strike action is likely to start next week at Sellafield.
It is understood the industrial action will take place from Monday, June 15 to Sunday June 21, but no specific details have been revealed.
Workers at the nuclear site in West Cumbria voted in favour of taking further industrial action on March 19.
The workers, who are employed by sub-contracting firms at the nuclear complex, took part the second ballot by union Unite this year.
Union members are demanding site-specific allowances, which they claim are paid at other nuclear sites across the country.
They first began industrial action in September last year. It concluded at the end of January. Workers did not strike from December 22 to January 2.
The union confirmed that its 1,720 members – who work for 31 firms – were reballoted.
The results of the most recent ballot show that there were 1,140 votes cast – around 66 per cent of those entitled to vote – and no ballot papers were spoiled.
681 voted in favour of continuing industrial action and 459 voted against.
Despite repeated attempts to contact Unite since March, the union has not replied to Cumbria Crack.
It sent out a statement today, Tuesday June 9.
It said nearly 2,000 construction workers were due to walk out over pay after the employer group failed to engage in discussions.
Unite added that it continued to make efforts to avert industrial action and remained committed to securing a negotiated settlement.
Unite regional officer Ryan Armstrong added: “Unite remains willing to enter into meaningful negotiations and the site negotiating team continues to work tirelessly to find a resolution.
“We have requested discussions so every opportunity to avoid industrial action can be explored. Our members simply want fair recognition for the work they undertake.”
A Sellafield Ltd spokesman said: “The industrial action taking place at Sellafield is the result of a pay dispute between some Unite union members and their employers.
“As the people involved are not employed by Sellafield Ltd this is not a dispute that we can resolve.
“Our priority, as always, is to maintain the safety and security of the Sellafield site.”
