The re-opening of an historic link across the Tyne could be four years late by the time work is finally finished.
The Tyne Pedestrian and Cycle Tunnel - between Jarrow and North Tyneside - was supposed to be back in action this month.
But thanks to delays installing new lifts this is now expected to be pushed back to April.
A spokesman for Newcastle City Council, which manages the tunnel on behalf of the North East Joint Transport Committee, said: “The tunnels are substantially complete, but there is still a challenging milestone that we need to complete before we can confirm when the public can start using them.
“This is the fitting of the glass enclosures to the new inclined lift and the commissioning of the inclined lift, which is complex and relies upon specialist contractors.
“Once this is completed and the lift is operating correctly, we’ll be able to announce the official re-opening date, which estimates show should open by April.
“We’re looking forward to having this wonderfully restored pedestrian and cyclist tunnels back into public use, as its provide a vital link for our communities crossing the Tyne.”
The project has been dogged by problems since a decision to renovate it was made a decade ago.
The tunnel closed in May 2013 for restoration work, which was supposed to be finished by 2015.
But delays due to the original contractor entering administration and the discovery of asbestos have seen this pushed back several times.
Last year, project bosses had promised work would be completed by the autumn, later revising that to December and then the New Year, before announcing the latest expected re-opening date.
Costs have also ballooned, from an original budget of about £6.9million, to an expected final cost of £15.65million.
The crossing opened in 1951 after taking four years to build at a cost of £833,000 – meaning renovations have now taken about two years longer than the actual construction.
James Harrison, Local Democracy Reporting Service