The reopening of the Tyne pedestrian and cyclist tunnels after a multi-million-pound revamp has been delayed again.
The tunnels have been closed since May 2013, and the work was originally due to be completed by August 2014.
But the scheme has been beset by problems, with the latest the discovery of more asbestos.
Now the tunnels are unlikely to reopen before summer 2017 - nearly three years behind schedule.
The cost of the refurbishment has already increased from £4.9m to £7.1m, and the latest delays are expected to push the bill even higher.
The tunnels link Howdon and Jarrow under the Tyne, and they were the first purpose-built combined pedestrian and cyclist tunnels ever built when they opened in 1951.
Their wooden-tread escalators, equivalent to the height of the Angel of the North, were once among the longest in the world.
The refurbishment work includes the replacement of two of the escalators with inclined lifts. The others will be restored and kept in situ as exhibits, but will not be operational.
Contractors GB Building Solutions were removing asbestos from the lining in the escalator shafts and lower halls, which have a problem with corrosion.
The work was already taking longer than anticipated, when the contractor went into administration in March this year.
Now, more asbestos has been discovered in the Grade II listed structure, leading to fresh delays.
Alastair Swan, principal engineer for the tunnels’ owner, the North East Combined Authority (NECA) said: “The discovery of further asbestos was made during our inspection of the tunnels following the collapse of the original contractor, GB Building Solutions.
"We had been advised that they had completed the asbestos removal works.
“We are now going out to tender for the removal or encapsulation of the remaining asbestos.
"We expect the asbestos works to commence early in 2016, and we are committed to the complete treatment of this hazardous material.
"We are looking to complete the asbestos work as quickly as possible to enable us to continue the refurbishment works.
“We continue to progress off-site works, including the manufacture of the new inclined elevators.
“We understand this setback will come as a blow to many tunnel users. We apologise for the inconvenience and ask for their continued patience and forbearance while we work to clean up the tunnels and restore this important pedestrian and cyclist link across the Tyne.”
The free-to-use, timetabled shuttle bus and a Night Service for shift workers continue to operate.
For more information about the pedestrian and cyclist tunnels, visit the website here.