Thousands of Environment Agency workers in England are to strike for four days later this month over 'endemic' low pay.
The latest action includes EA staff working on coastal sea defences, protecting rural areas from floods, tackling water pollution and waste crime.
The strike will commence on Friday 14 April until Monday morning 17 April, UNISON, one of the UK's largest trade unions, confirmed.
It said that "endemic low pay and uncompetitive wage rates" meant the Environment Agency was "struggling to hold on to experienced staff and recruit new employees".
This "staffing emergency" meant that EA's incident response and enforcement teams were "already too thinly stretched" to continue its work.
UNISON said the government’s 'refusal' to allow the EA to improve the pay increase of 2% plus £345 given to staff in the autumn meant workers had "no alternative but to reluctantly strike again".
Where there is a threat to life or property from major incidents like flooding, EA officers will step in as emergency ‘life and limb cover’ during the strike.
UNISON head of environment, Donna Rowe-Merriman said: "The government needs a properly staffed Environment Agency if natural habitats and water sources are to be protected.
"But with too few experts on its books, the agency can’t possibly punish the polluters and keep everyone safe."
She added: “Therese Coffey should stop ignoring the plight of these invaluable workers and start tackling the growing staffing problems at the Environment Agency.
“Hourly rates are so low, some staff had to be given an emergency pay rise at the start of the week or their employer would have been in breach of minimum wage laws.
“It’s time the government called in the employer and the unions to settle this damaging dispute once and for all.”
In January, more than 300 call-centre workers at the Rural Payment Agency (RPA) held a strike over pay.
The PCS, which represents workers employed by government departments, had asked for a 10% pay increase, better job security and no slashes to redundancy terms.
Earlier this month, a strike by 150 animal feed mill workers employed by manufacturer ABN was called off after they voted to accept a two year pay deal worth 13%.
