Deep sea divers working in the oil industry have voted for strike action over their pay demands.
Oil and gas production could be hit if the strike goes ahead
Workers in the North Sea are seeking a 50% rise and had been considering industrial action after being offered a 15% increase over three years.
The RMT union balloted divers and support workers on the offer and they rejected it by 640 votes to two.
Union chiefs warned that only a "dramatically improved" deal would stop the strike going ahead on 1 November.
The RMT said divers were carrying out probably the most dangerous job in the North Sea.
They go below the cold waters to carry out work on wells and pipelines.
However the divers claim pay rises have been modest at best in recent years.
If the action proceeds then oil and gas production could be severely disrupted.
RMT general secretary Bob Crow said: "The all-but-unanimous vote shows exactly how angry our members are at an offer that simply fails even to dent the chronic pay slippage they have had to endure for more than 20 years.
"We hope the employers will take note of this tremendous ballot result and table an offer that redresses the real-terms pay cuts and sub-inflation deals our members have been expected to swallow for so long.
"No-one can argue that the industry cannot afford to pay decent rates to people who do some of the most difficult and dangerous work in a particularly difficult and dangerous industry."
Steve Harris, of the UK Offshore Operators Association (UKOOA), said: "Strike action by any group within the industry is obviously disappointing.
"Anything that compromises the competitiveness of the UK in what is a globally competitive market place is deeply regretted and strike action harms the attractiveness of the UK in just the same way that regular tax increases do.
"The industry will obviously do all it can to minimise the effect of any action and we very much hope that it can be avoided entirely."