The leader of the UK's biggest rail union has warned that rail workers could also strike on days when firefighters are taking industrial action.

Bob Crow, leader of the Rail Maritime and Transport workers union, said the simultaneous action could come about because of safety concerns for emergency fire cover.

Some 19 London Underground stations already face closure during the Fire Brigades Union action due to their dependence on the emergency service.

But Mr Crow said the RMT would be holding talks with all rail operating companies and London Underground to discuss safety issues during the fire strike.

While they (firefighters) take action we are not having our members' safety compromised

Bob Crow, RMT leader

Full-time firefighters voted on Friday to walk out for a series of six national strikes - the first for 25 years - in support of a 40% pay claim.

Mr Crow said that if crews working for rail companies and London Underground were worried about safety, a ballot could be called.

Routes shut

Speaking on BBC Radio 4's PM programme, he said: "We will be meeting with all the train operating companies this week and with London Underground and we will be saying do you think it is as safe with Green Goddess as it is with the fire appliances.

"If the answer is 'no' then we believe London Underground and the train operating companies should shut those parts of the lines down."

Strike dates

0900 29 October to 0900 31 October (48 hours) 0900 2 November to 0900 4 November (48 hours) 0900 6 November to 0900 14 November (8 days) 0900 22 November to 0900 30 November (8 days) 0900 4 December to 0900 12 December (8 days) 0900 16 December to 0900 24 December (8 days)

He said those train lines with tunnels and deep line tubes would need to shut for the duration of the firefighters' dispute.

If there is a disagreement on safety grounds between employers and workers, then the RMT will ballot members on strike action, he added.

"We've had King's Cross fire, we've had Hatfield, we've had Potters Bar and we've had Ladbroke Grove - we are not having any more safety being compromised," he said.

The practice of secondary action in support of another union was outlawed by the Thatcher government but Mr Crowe denied the RMT was contemplating secondary action under the veil of safety concerns.

Pay demand rejected

"While they (firefighters) take action we are not having our members' safety compromised," he said.

The 50,000 members of the FBU voted nine to one in favour of action.

The vote came after local authority employers rejected the union's demand for a 40% pay rise, offering instead a 4% increase as part of an interim deal.

On Saturday the Retained Firefighters' Union (RFU) said it wanted more money for its members, but did not believe firefighters should strike.

RFU president Colin Ive told the BBC: "We fundamentally support the principle of increased pay for firefighters ... what we object to is the method - the strike method is not the right way."

The union favoured co-operation with an independent inquiry set up by the government to reach a negotiated settlement.

And he described the FBU's demand for a 40% wage rise as "incredible".

"The last thing they [RFU members] want is blood on their hands," he added.

'Heavy heart'

The first walkout will begin next Tuesday, 29 October, and last for 48 hours. Others will stretch to as much as eight days, with one ending the day before Bonfire Night and another on Christmas Eve.

The army - backed by smaller numbers of Royal Navy and RAF personnel - is on standby to provide cover during the strikes with 827 ageing 'Green Goddess' fire engines.

Most of those voting for action said they had done so with a "heavy heart", feeling they had no other choice.

But the strike action was described as "dangerous and damaging" by the Deputy Prime Minister John Prescott.

The government's independent review on pay is not scheduled to report until December.