British North Sea oil and gas workers said they'll vote on a labor stoppage after talks broke down with the industry over working conditions.

Trade unions Unite and GMB said talks broke down with industry group Offshore Contracts Association on changes to working conditions in the North Sea. Union officials had said there were safety concerns about shift lengths.

GMB National Officer David Hulse said in a statement Thursday some progress was made in recent talks with industry representatives, but not enough to resolve the dispute.

"We remain available for talks should the employers want to pull back from going ahead with the unilateral changes to working practices that has provoked this dispute," he said.

In March, Hulse said there was "overwhelming" support for labor strikes. Members were frustrated with the lack of risk assessments made regarding shift rotations.

The BBC's Scottish bureau reported Wednesday oil major BP was proposing a three-week on, three-week off shift pattern, a change from the current two-week on, three-week off, shift. BP was quoted as saying the move was meant to ensure the "long-term sustainability" of operations in the North Sea.

BP in April said it's in the middle of a five-year $4.5 billion investment program in the North Sea.

Operating expenses in the North Sea are up 8 percent while revenues for oil companies working in the region are at their lowest levels since 1998. Combined, those elements translate to a negative cash flow for North Sea operators.

In response to the March support for labor action, Bill Murray, chief executive officer at OCA, said inflation was indicative of the need to increase productivity and reduce redundancies.

"Strike action would only serve to make investment in the North Sea less attractive and jeopardise the long term future of the industry," he said in March.