A strike by more than 1,000 firefighters over the next eight days is now "almost inevitable", union leaders warned after a fresh clash with a fire authority over jobs.
Members of the Fire Brigades Union (FBU) on Merseyside will walk out at 10am on Thursday for four days followed by another four-day stoppage two hours after the first one ends.
The union has accused the fire authority of planning to cut 120 jobs, one in 10 of the workforce, 15 emergency control operator posts and introduce a new shift system which officials said would lead to firefighters spending 96 hours at a time at fire stations.
No military cover will be provided during the strike which will leave Merseyside with just 160 firefighters and 20 fire engines, less than half the normal number.
Les Skarratts, the union's Merseyside Brigade Secretary, said: "These are some of the worst cuts ever proposed in any local fire service and will inevitably damage our operational capability.
"The planned cuts are ill thought out panic measures which are the result of a failure of financial management.
"The proposal for a 96-hour shift, where fire crews can't leave the station will take us back to the 1930s."
Mr Skarratts said there was now very little time left to resolve the dispute and accused managers and councillors of refusing to budge on their "hard line" stance.
Merseyside's Assistant Chief Fire Officer Bill Evans accused the union of having "total disregard" for public safety adding: "Withdrawing labour is not resolving the issue and I am sure the residents and businesses of Merseyside will share my disappointment that the FBU are taking this stance instead of taking a more responsible approach."
The authority claimed its proposals offered an opportunity for firefighters to work differently and earn more money adding that there were no plans to sack any firefighters.
