The fire service has asked people not to hold their own firework parties – and warned of a delayed response – during the four-day strike action being staged by firefighters.

Members of the Fire Brigades Union will walk out at 6pm on Friday in their latest round of industrial action. The strike, which the Government described as unnecessary, will end on Tuesday.

Cambridgeshire Fire and Rescue Service said it is putting back-up plans in place to ensure there is fire cover across the county and that it can respond to emergency calls. But it has asked the public to attend organised firework displays, stating that, because of the length of the strike, there will not be a normal level of service.

Chief fire officer Graham Stagg said: "This four-day continuous strike is a challenge for us to provide cover. We will have cover in place with officers crewing a number of fire engines on a 24/7 basis, together with those of our on-call firefighters who are not joining the industrial action, but it will be fewer fire appliances available than previously. Although we will respond as quickly as we can, people should expect a delayed response when calling the fire service over the four days."

The fire service added that it would not know how many fire engines it would have available until the strike started.

Firefighters have been in conflict with the Government about changes to their retirement age, claiming the idea of making members work until their 60s could put people's lives in danger. The Government says firefighters have one of the most generous pensions in the public sector in recognition of the risks they take.