Thousands of staff and volunteers are working hard to keep the capital working during the "pointless" Tube strike, London Underground said.
TfL said the Victoria line was now running fully with the Central line running to Holborn and the Jubilee line running through from Wembley Park to Stratford.
London Underground managing director Mike Brown said:
Thousands of staff and volunteers are working hard this morning to keep London working and our customers informed in the face of this pointless strike.
More London Underground staff have come to work this morning than during the strike back in February, and a record number of London buses are operating.
A Transport for London spokesman said the RMT could not "claim a shut down in any sense of the word."