We've got to deliver on the passengers' agenda

Stephen Byers

But the minister also admitted that "certain aspects" of Britain's railway system had worsened under Labour.

The comments were prompted by Europe Minister Peter Hain, who said in a magazine interview that Britain had "the worst railways in Europe" - a suggestion rejected by Downing Street.

However, the prime minister's official spokesman did admit that mistakes had been made over transport policy, particularly by sticking with Railtrack - since put into administration by Mr Byers - during its first term in office.

Election timetable

During a BBC interview Mr Byers issued a pledge to Britain's beleaguered rail passengers, hit by a series of strikes since the New Year with more looming on the horizon.

"In three years time, or whenever the next general election is called, if we have not got a railway system which has got better punctuality, which is more reliable, which is safe, which is more clean and more comfortable then we will be held to account and that's how it should be," he said.

We started transport investment far too late... We should have been more radical earlier

Peter Hain

"I am confident and I more than happy as secretary of state for transport to be judged on whether I have delivered on that passengers' agenda."

The BBC's political editor, Andrew Marr, said the pledge appeared to be a "hulking great hostage to fortune", and one commuters were unlikely to forget.

The pressure on Mr Byers, already under fire for taking a holiday while parts of the rail network were paralysed by strikes and then refusing to intervene, was maintained by Mr Hain's comments in the Spectator magazine.

He said transport investment was started "far too late" and the government "should have been more radical earlier".

Hain 'rebuked'

Mr Byers said he was relaxed about the remarks, saying: "Peter Hain is saying, and I believe this, that we do not have a railway fit for Britain in the 21st Century."

Mr Blair's official spokesman said there were no statistics available to make an accurate comparison and so Mr Hain's remarks were an "opinion".

The spokesman added that, like all ministers, Mr Hain knew the government had been right to lay the ground in its first two years to provide the economic stability needed for extra investment.

Hain has made a "pretty devastating admission", say the Tories

Later the minister sought to clarify his position and give his backing to the government's current 10-year transport plan.

Reversing decades and decades of under investment was "like turning an oil tanker around", he said.

But the Conservatives seized on the interview remarks, with shadow transport secretary Theresa May saying Mr Hain was "simply stating the obvious".

"By admitting that Britain has the worst railways in Europe, Peter Hain is telling rail passengers what they already know - that they have been suffering for far too long.

Meanwhile Gavin Strang, Labour ex-minister for transport, argued for the rail industry to be renationalised.

"It's a bold policy, but I think that is what is needed," he told the BBC, although Mr Byers is ruling out renationalisation.

Our door is open to them to meet with us at any time if they have any further ideas

ScotRail acting managing director, Nick Brown

The debate continued as rail unions at two UK companies met management in efforts to avoid further strike action in Scotland and the north of England.

But talks between ScotRail and the rail unions RMT and Aslef broke down on Thursday evening without agreement.

ScotRail acting managing director Nick Brown said no further talks were planned, but added: "Our door is open to them to meet with us at any time if they have any further ideas."

There appears to be little hope of resolving a dispute at South West Trains where unions have threatened a repeat of their two 48-hour strikes that caused heavy disruption in the south.