Offshore catering workers have rejected an offer of new terms and conditions from their trade body.
The Unite and RMT unions said the latest proposals from the Caterers Offshore Trade Association (Cota) would freeze pay at existing levels.
More than 60% of workers who took part in a ballot by phone turned the offer down. The unions will now consult with workers.
Cota expressed disappointment at the result of the consultative ballot.
Its chairman Andrew Thomson said: "We are committed to ongoing and open dialogue with employees and the unions."