Two fundraisers are gearing up for a race against time beneath the streets of five European capital cities.

Just minutes could be the difference between success and failure as they tackle a five-day marathon aiming to visit every underground station in London, Paris, Brussels, Berlin and Vienna.

Alan Perks, of Norreys Road, Didcot, and John Holman, of Columbia Way, Grove, have spent nine months planning the epic 880-station tour, with military precision.

They hope their Five Cities Tube Challenge will raise thousands of pounds for Cancer Research UK, in memory of Mr Holman's wife, Angela, who died of the disease in February, aged 45.

But anything, from a delayed train or an unplanned station closure, could spell disaster for their mammoth trip, which begins on London's Metropolitan Line at 5.28am on October 27 at Amersham.

Mr Perks, 48, who is married to Tracy, 43, believes they will be the first people ever to tackle five cities in five days. He said: "We raised some money for a local pre-school by visiting all the underground stations in London a couple of years ago, and we wanted to do something in a similar vein.

"Someone suggested doing London and Paris, making it two days, and we thought about doing three days and it went from there.

"If everything goes to plan it should be possible, but if there is just one closure we can't do it. It's going to mean no sleep for a week, but I'm looking forward to it."

The father-of-four said: "We are towards the end of the planning stages now, we've been planning it since January when I approached my friend.

"We have been using the underground system's journey planners online mainly to work out the best combination and routes to use.

"It has been very, very meticulous and time consuming, especially since some of the stations close at certain times."

The journey involves precise timing to make overnight trains and flights to connect all the cities.

Mr Perks said: "I do think it's possible to achieve. With all the planning I've put into it, it can't fail."

Stepfather of three, Mr Holman, 51, said he was proud to be doing the trip in memory of his wife.

He said: "It's going to be really hectic. We'll be running down the escalators and down the steps. We don't get off at each station, but we will note down the time we pass through it. "Angie would have been very proud. Planning the trip has helped me focus on the last few months which have been nothing short of a nightmare really. We just want to raise as much money as we can."