Firefighters are to strike for four hours next week in a row over pensions, the Fire Brigades Union said.
Almost 80 per cent voted in favour of industrial action in a ballot which ended earlier this month.
Union officials had left the strike to the last possible moment to allow for the possibility of a negotiated settlement.
The strike will take place on Wednesday, September 25.
Fire Brigades Union (FBU) general secretary Matt Wrack said: “This initial strike is a warning shot to Government.
“Firefighters could not be more serious about protecting public safety and ensuring fair pensions.
“Governments in Westminster and Cardiff have simply refused to see sense on these issues.
“It is ludicrous to expect firefighters to fight fires and rescue families in their late 50s: the lives of the general public and firefighters themselves will be endangered.
“None of us want a strike, but we cannot compromise on public and firefighter safety.”
The county fire service urged people to take measures to reduce the risk of fire in their home earlier this week in light of any strike action.
Station manager Warren Ellison said: “This is good advice for everyone to follow at all times, and is even more important during the coming weeks and months.
“We have contingency plans in place and will be continuing to respond to emergencies, but this is a testing time for fire and rescue services across the country so anything that can be done to reduce the risk of fire is definitely a good idea.
“Resources will be stretched so we would also like to remind people that as always, only call 999 in an emergency.”
Firefighters in Scotland will not strike next week while union officials are discussing the Scottish Government’s most recent proposals.
But as a settlement in Scotland has not yet been found, the union’s strike ballot could still result in industrial action there too.
The walkout will take place for four hours between midday and 4pm.