Hundreds of government health and safety inspectors are to stage a one-day strike over pay following the collapse of talks.
About 2,700 staff will take part in the strike on Monday
Health and Safety Executive staff, including inspectors and scientists, will walk out for 24 hours on Monday.
About 2,700 staff will follow up the action with a work-to-rule.
Their unions, the PCS and Prospect, said a pay offer meant the most experienced staff would receive a rise of only 1.5% this year.
The negotiations officer for Prospect, Richard Hardy, said the offer was
"Moral in the HSE is low enough as it is without forcing our members to take pay cuts," he said.
"We are very worried that our members will vote with their feet, stripping
HSE of years of experience which will have a horrendous impact on workplace
safety throughout the UK."
The strike will be the first involving health and safety inspectors for more
than 20 years.
Unions said major incidents and court cases would be given dispensation from
the industrial action.
Steve Farley, negotiations officer for the PCS, said the union's claim for a
minimum of 2.6% was "reasonable and affordable".