A section of the Metropolitan line affected by a track fault will remain closed this week, Transport for London has said.
Services between Baker Street, where the problem has occurred, and Aldgate will be suspended until November 9 due to the issue.
The fault is reportedly a crack in the points, which are essentially a complex set of junctions allowing the Metropolitan line and other lines to converge at Baker Street.
While the fault was detected last week, it is understood the repairing requires a custom casing, which is why there is a delay in fixing the issue.
Transport for London has said minor delays are expected on the rest of the line.
Passengers have been advised to change at Baker Street for Bakerloo, Circle and Hammersmith & City line services or use the Jubilee line from either Finchley Road or Baker Street.
Travellers are advised to allow more time for their journey and to use the TfL journey planner.
It comes just weeks after one of the London Underground’s busiest lines was plagued by delays and knock-on congestion due to a mystery fault to the signalling system.
The Northern line was blighted for days with signal failures near Stockwell station that meant far fewer trains than normal had been able to run on the line.
Stockwell is normally served by about 15 Northern line trains an hour in each direction but this fell to between six and eight trains an hour.
Rather than waiting up to four minutes for a train, some passengers had to wait as much as 10 minutes between services.
