On a 69% turnout, 87% of members voted in favour of industrial action short of a strike with only 15 members voting against. The vote follows an earlier ballot in February where members rejected a tabled pay deal that provided an average 2.5% increase for Prospect members.

According to a story in the Western Morning News, surveyors in the Westcountry, based in Falmouth and Plymouth, inspect and license the region's passenger boats, carry out port state control inspections and monitor British-flagged vessels overseas.

The action, from May 21, will take the form of a ban on overtime. It is expected to lead to a backlog in the vital survey work undertaken at ports across the country.

Prospect negotiator John Ferrett said: ‘The below inflation award compounds existing frustration at the disparities in pay between MCA surveyors and comparable Department for Transport colleagues in the Marine Accident Investigation Branch who are paid literally twice as much.’

A spokesman for the MCA told the WMN: ‘There is no intention of reopening negotiations. We have got contingencies in place to cover their action.’

In April, volunteer coastguard teams around the UK withdrew from responding to call-outs following a row over compensation for injuries.