Commuters should brace themselves for transport misery this week thanks to the start of a planned 72-hour Tube strike.

More than 2,300 maintenance workers are set to walk out from 6pm today over fears of job losses as a result of the financial collapses of Tube maintenance firm Metronet.

The leaders of three unions, the RMT, The Transport Salaried Staffs Association (TSSA) and Unite have said they want guarantees that members' jobs will not be put at risk by the collapse of Metronet.

RMT's general secretary Bob Crow said: "There has been no contact over the weekend from Metronet or the administrator so as far as we are concerned the strike will definitely go ahead."

The unions also warned of the possibility of a second 72-hour strike on September 10 if the situation was not resolved.

A Transport for London spokesman said: "We have been informed that the TSSA and Amicus Section of Unite trade unions will be meeting on Monday and we fully expect them to call off the strike as they have received all of the assurances they have requested."