Talks aimed at averting a strike by firefighters at the Sellafield nuclear site have been adjourned until next week.
The GMB union said next Thursday’s meeting will be the last opportunity to resolve a dispute over pay.
GMB members have already voted two to one in favour of a series of 24 hour strikes starting in July.
The dispute is over pay grading, with the firefighters saying they have been performing roles beyond what they are paid to do, such as paramedic work.
GMB official Chris Jukes said: “Discussions between GMB and Sellafield management took place in a professional and reasonable manner and there were wide-ranging discussions about pay.
“However, the bottom line is management made an offer which has already been rejected by our members and it will take an improved offer to settle this matter, which has been unresolved for several years.
“GMB agreed to Sellafield’s request for more time and we have adjourned the talks until the end of next week so management can reflect on their offer.”