London Underground called today for a review of engineering work after fresh delays to Tube services caused travel misery during the morning rush-hour.
The Central, District, Jubilee and Hammersmith & City lines were all hit by a combination of late finishing engineering work and a broken-down train.
London Underground's managing director, Mike Brown, said: "London Underground is engaged in a massive upgrade programme to replace track, signals and trains to provide more capacity and smoother journeys.
"Works to improve the railway between East Ham and Barking over the weekend were not completed on time by our contractor Balfour Beatty, which meant unnecessary disruption to District and Hammersmith & City line services.
"This is simply not good enough and we are meeting with Balfour Beatty now to demand a full review of the works and that they ensure there is no repeat in future.
"I apologise to our customers for the disruption to their journeys this morning, and assure them we are working flat-out to improve reliability across the Tube."
Bob Crow, leader of the Rail, Maritime and Transport union, said: "Hundreds of thousands of commuters face yet another Monday of chaos as the poisonous cocktail of failing infrastructure and maintenance cuts hits home yet again.
"This crisis management of the Tube is now out of control and leaves us on course to become an international laughing stock in the run-up to the London Olympics."