Derek Smith, who becomes managing director of London Underground tomorrow, said he could not guarantee that this autumn's target date would be met.
Mr Smith said staff working on the project were confident the Tube line would be finished in time for the opening of the Dome, but the prospect of a tortuous journey across London for visitors to the Greenwich site remains.
Failure to meet the deadline would be a huge embarrassment to the Government which has staked so much on the Dome's success. Its transport managers would face a logistical nightmare.
The line is due to open in three phases with the first, between Stratford and North Greenwich, scheduled for this spring. The new track is now in place, the finished stations are covered in bubble-wrap and test trains are already running on part of the track but, according to Mr Smith, there is a great deal of work still to be done.
The Government has allocated an extra pounds 365m to London Underground for the two years to April 2000, when the public subsidy is due to be scaled down as the private sector steps in.
One worry, said Tony Travers of the London School of Economics, is that train drivers on the Jubilee Line, like the electricians working on its construction, will use the political need for success as leverage to get more money out of London Underground.
A more immediate problem for Mr Smith is the looming threat of strike action by Underground staff unhappy about the planned partial privatisation of the system, which would see 6,000 employees transferred to new companies.
Mr Smith, who was appointed by the Deputy Prime Minister, John Prescott, to the pounds 150,000-a-year post overseeing the introduction of a public private partnership (PPP), insists that Mr Prescott has given repeated guarantees over pay, conditions and pensions.
The PPP compromise was announced by Mr Prescott last March as a way of providing the ageing infrastructure of the Tube network with a desperately needed pounds 7bn investment over 10 years.
Campaigners had previously argued for Treasury restrictions on the Public Sector Borrowing Requirement to be relaxed so that London Underground could get loans at a cheaper rate, but this was rejected.
Under the PPP, London Underground would hand over its infrastructure of tracks, stations, trains, and signalling to the private sector for a period of 30 years and lease it back as a train operator.
The details of how such an arrangement could work are being thrashed out by government advisers and London Underground management. Mr Smith insists the plans will be carefully tested "so that the public sector gains".
Mr Smith, a proponent of the Private Finance Initiative in his previous job as chief executive of King's College Hospital in south London, says it is the only way of guaranteeing a sustained level of investment "We need modern signalling and stations so that we can move as many people as quickly as we can without compromising safety," he said. "People want their journey to be a non-event and that is what we are aiming for."
However critics are already expressing doubts that the PPP can be made to work in a mutually beneficial way.
Louise Hudson, of the Capital Transport Campaign, said the obvious way for London Underground to pay for the leases would be to increase fares.Reuse content