A COMPREHENSIVE review into the state of the Tube has been launched by the London Assembly.

Members will assess the network “line by line” to judge the success of upgrade work which began eight years ago, and see whether the current performance of the train system is up to scratch.

The review comes after months of negative headlines for Transport for London, sparked by lines closures, delays, breakdowns, and faults.

The timetable for upgrading the Northern, Piccadilly, and Jubilee Lines - which will boost capacity by 30 per cent by 2020 - has slipped, assembly members say, and they add that some indicators show performance of Tube services is deteriorating.

The inquiry will focus on the period since 2008, when TfL took over control of maintenance and upgrade work, with public hearings scheduled for May 17and June 14 to gather the views of the public.

Caroline Pidgeon AM, chairman of the transport committee, said: “With passenger numbers at record levels and several line upgrades behind schedule, it’s time for an in-depth look at the service Londoners get, the improvements we’ve seen so far, and ways to get the upgrades back on track.”

The committee is planning to publish a report at the end of the inquiry, and deliver findings and any actions they believe the Mayor of London Boris Johnson and TfL should take.