Millions of passengers are preparing for travel chaos because of a strike by London Underground workers in a bitter dispute over jobs.

Thousands of members of the Rail Maritime and Transport (RMT) union and the Transport Salaried Staffs Association (TSSA) will strike for 24 hours from 5pm on Monday in protest at plans to axe 800 jobs.

The walkout, to be followed by further stoppages in October and November, will disrupt Tube services as MPs return to Parliament after the recess and many people get back to work after the summer break.

The first of a wave of strikes by LU workers started at 7pm on Sunday when up to 200 maintenance staff at depots on the Jubilee and Northern lines launched a 24-hour walkout in a separate row over pay and conditions. The Alstom-Metro employees will also strike for the same time on October 2, November 1 and November 27 after rejecting an "insulting" sub-inflation pay offer.

The RMT claimed a circular had been sent to staff seeking volunteers to help run services during the main strike. It said no operational licence was needed if people volunteered to support staff turning up for work, and added that lapsed licences could be renewed.

RMT General Secretary Bob Crow said: "There do not appear to be any corners that London Underground are not prepared to cut in order to bulldoze through their lethal cocktail of job and safety cuts. Sending out a few volunteers without the necessary operational licences and training to try and run a few trains is a disaster waiting to happen."

Transport for London denied the RMT's allegations and said it would never do anything to compromise safety on the underground. Mayor Boris Johnson has announced contingency plans, with 100 extra buses laid on, escorted bike rides, marshalled taxi ranks, and capacity for 10,000 more journeys on the River Thames.