Firefighters in Hertfordshire are to strike over eight consecutive days in an ongoing row with the government.
The Fire Brigades Union have already staged walk-outs over 24 days since strikes began in September last year and firefighters have gone on strike for more than 160 hours.
The latest action will be held over three hours each day from August 9 until August 16.
Hertfordshire Fire Brigade Union secretary Tony Smith said "unsafe and unrealistic" proposals will see firefighters working longer and having their pensions cut.
The row centres on plans to raise firefighters' retirement age from 55 to 60 and increase their pension contributions.
Mr Smith said: "We have put our proposals to the Government, who are refusing to listen so we have to take action.
"Obviously this is the last thing we want to be doing but we have to make a stand.
"We are having the evidence ignored and the Government are not interested in what we have to say.
"It is ludicrous to expect firefighters to work until they are 60. We are not asking for the earth but we will continue to take action until we are listened to."
The strikes will run between 12pm until 2pm and 10.59pm until 11.59pm.