The London Mayor has been called on to come up with an action plan to tackle the continuing disruption and delays on the Northern Line Tube service.
London Underground oversaw repairs
London Assembly members voted unanimously during an emergency debate on a motion calling for the Mayor to report back on progress next Tuesday.
London Underground (LU) used emergency powers to oversee remedial work by Tube Lines and its subcontractor Alstom.
On Friday, almost half the line's fleet did not run due to brake safety checks.
Last week, the emergency braking systems on Northern Line trains failed, so LU introduced daily safety checks and put an extra driver in each train. This led to a reduced service and severe delays.
Although the full fleet is now running, there have been further delays as a result of signal failures and maintenance works.
London Assembly deputy chairman Conservative Brian Coleman is a councillor for Barnet and Camden which is served by the Northern Line.
"In the 90s it was known as the Misery Line. It's now living up to its old reputation," he said.
"I want the Mayor to draw up an action plan. No more hot air. No more rows about who's at fault. I want action."
An LU spokesman said it felt appropriate action had been taken by taking an emergency directive out on maintenance contractor Tube Lines. They, in turn, took one out on Alstom.
A spokesman for Tube Lines said it had provided LU with a full fleet of trains since Saturday and that it was not satisfied with Alstom's performance.
Alstom said it had been working closely with LU and Tube Lines.