LU says engineers are working flat out to rectify the line's problems

But LU has told BBC London it plans to reinstate services on the line's eastern end by the beginning of April.

This follows an announcement that one of the trains modified since the incident successfully travelled the length of the line and back again in a strictly-supervised run.

LU says further tests are needed before this limited service can be started.

More than 30 passengers were hurt when a train came off the line which runs from West Ruislip in west London to Epping in Essex.

'Work to do'

The service will be restarted between Bethnal Green and Woodford and if successful it will be extended to Loughton and then Epping.

LU says if the trains are not overcrowded the west side of the line from Ealing Broadway to Marble Arch will then be opened.

There are currently no plans to introduce the service on the far west of the line to West Ruislip, or the central section where the derailment happened.

LU managing director Paul Godier said: "I am sorry that I cannot give customers a cast-iron date for the return of the Central Line."

He added that there was still "much work to do" but engineering teams were working flat out to rectify the problem.

The line's 85-strong fleet of trains have been undergoing modification since the incident on 25 January.

RMT Union leader Bob Crowe said not enough was being done to help Londoners while the line is out of use.