Fire strikes will force Tube and rail shutdown Â

London Underground could face total shutdown during next week's 48-hour national firefighters' strikes – if, as is feared, transport workers walk out over safety concerns.

Tube management had hoped to limit the impact of the firefighters' stoppage to the closure of only 19 stations, but it is now expected that the overwhelming majority of Tube services will not run next Tuesday and Wednesday.

On the national rail system, unions told drivers and other workers yesterday that they will support walkouts when they have misgivings about the safety cover provided by Ministry of Defence Green Goddess fire engines.

The Prime Minister warned that giving in to the firefighters' 40 per cent pay demand would create "havoc" across the public sector. Tony Blair said there was "no way" any government could accept such a pay demand because it would force up mortgage interest rates.

Fire service management want the union to postpone stoppages until after a Government-backed inquiry into the service and the pay of its employees – expected to report in mid-December.

The Government has agreed to meet in full the cost to local authorities of using the army and police to provide emergency cover in any stoppage. In a deal cut with councils late last week, the funds will be supplied as long as fire authorities hand over any money saved from not paying firefighters' wages.

The Government stepped up plans for the military to provide emergency cover, with a meeting of Downing Street's emergency committee, Cobra, on how to deal with the 36 days of pay strikes by firefighters. However, the Fire Brigades Union (FBU) claimed last night that the Government had drawn up a "wholly inadequate" plan to provide cover during the firefighter's strike.

Andy Gilchrist, the general secretary of the FBU, held a meeting with the Fire Service Minister, Nick Raynsford, to discuss how firefighters might suspend industrial action in the event of a major "crisis". But Mr Gilchrist said afterwards: "Trying to cobble together an alternative plan for the fire service is not the way to deal with this dispute."

Derek Simpson, joint general secretary of Amicus, said: "We will encourage any groups of workers whose safety is legitimately compromised by lack of fire cover to leave work. This would not be secondary action. It would be an evacuation."

London Underground pointed out the Health and Safety Executive had ruled the network could run safely if the 19 deep stations were closed. The Strategic Rail Authority said a full "risk evaluation" had been completed and walkouts on the national network would constitute "callous opportunism".

The Government is hoping that John Monks, the general secretary of the TUC, will put pressure on the FBU to adhere to its 1979 code of conduct, which says unions have a duty to provide services "essential to the health and safety of the public".