Workers at the Dounreay nuclear plant in Caithness will vote on industrial action.

Union members at the former fast reactor have rejected a 1% pay rise offer from Dounreay Site Restoration Limited (DSRL).

Dounreay Joint Trade Unions (DJTU), which incorporates the GMB, Unite and Prospect unions, claims the offer is not in line with other parts of the industry.

DSRL says the deal is comparable to recent pay increases in the sector.

Union spokeswoman Sandra Owsnett said: "This is the lowest pay offer that has been made to the workforce since [DSRL parent company] Cavendish Dounreay Partnership were awarded the contract to decommission the site, yet, over the same period, their profits have increased substantially.

"The 1% offer is not in line with other parts of the nuclear industry, or even Cavendish Nuclear and other Babcock businesses in Scotland, which have all secured better offers."

A DSRL spokeswoman said: "The pay offer that we have made is comparable to recent nuclear decommissioning industry pay increases and is above inflation.

"We remain committed to engaging with the trade unions and staff but due to the sensitive nature of these negotiations, we are unable to comment further."

The nuclear plant at Dounreay opened in the 1950s and was taken offline in 1993. It is now at the centre of a multi-billion pound decommissioning programme.