Transport disruption across the capital will begin on Monday evening as London Underground staff strike for 48 hours over plans to close ticket offices.
The disruption will last for two weeks, as a further 72-hour strike is set to take place after the bank holiday weekend if the dispute is not resolved.
There have been reports that the Rail, Marine and Transport Union and tube management will reach a last-minute deal, yet the strike is expected to go ahead as planned. The walk-out is being staged in response to the London Underground's modernisation plans, which could result in 960 jobs being axed.
Mick Cash, the RMT's acting general secretary, told the BBC: "This dispute is solely about cash-led cuts to jobs and services that would decimate Tube safety."
Phil Hufton, London Underground's Chief operating Officer, said: "Our plans will radically improve the service we offer Tube customers. The whole Tube station will effectively become a personalised customer service centre, with more staff visible and available to help customers."
He added: "We've provided guarantees that not a single member of staff will be forced to leave LU, that no supervisors must 'apply for their own job' and we are seeking ways to ensure that no member of staff sees their pay cut as a result of these changes."
When will the strike begin?
If strike action does take place, services will be affected from 9.30pm on Monday 28 April. The strike will last 48 hours, disrupting services throughout Tuesday 29 and Wednesday 30 April.
On Tuesday and Wednesday a limited number of trains will run from around 7am until around 11pm, but services in central London may finish significantly earlier - from 9.30pm.
Which lines are affected?
Some stations will be closed and Transport for London have advised those travelling to check the website for updates. Services will not return to normal until Thursday 1 May and not all of the planned services may be able to run.
Bakerloo: Trains between Queen's Park and Elephant and Castle are expected to run. The service may not run all day and will not stop at Edgware Road, Embankment, Kilburn Park, Lambeth North, Maida Vale, Piccadilly Circus or Regent's Park.
Central: No service will run in the central area. Trains are expected to run between Epping/Hainault and Leytonstone around every ten minutes. The service may extend to Holborn. There is a limited service between West Ruislip and White City, which may be extended to Ealing Broadway.
Circle: See District and Hammersmith & City.
District: Trains are expected to run between Wimbledon and Barking, the service may be extended to Westminster. Services will run between Ealing Broadway and Tower Hill. These trains will not stop at Aldgate East, Blackfriars, Gloucester Road, Sloane Square, Stepney Green or Temple stations.
Hammersmith & City: Trains will run between Hammersmith and Aldgate. The trains will not stop at Barbican, Euston Square or Great Portland Street stations.
Jubilee: Trains will run between Wembley Park and Stratford. They will not stop at Bermondsey, Canada Water, St. John's Wood, Southwark, and Swiss Cottage stations.
Northern: Trains will run over the whole line via both the Bank and Charing Cross branches in both directions. Trains will not stop at Angel, Borough, Chalk Farm, Charing Cross, Clapham North, Clapham South, Colliers Wood, Embankment, Goodge Street, Hampstead, Leicester Square, Mill Hill East, Mornington Crescent, Old Street, Oval, South Wimbledon, Tooting Bec and Warren Street stations.
Piccadilly: Trains will run between Acton Town and Heathrow Terminals 1, 2 and 3, and between Arnos Grove and Cockfosters. These trains will not stop at Heathrow Terminal 4, Heathrow Terminal 5, Hounslow West or Southgate stations.
Heathrow Express: A limited service will run on Tuesday 29 April and Wednesday 30 April. Check Heathrowexpress.com for details.
Victoria: Trains will run between Seven Sisters and Victoria and the service may extend to Brixton. The trains will not stop at Pimlico, Vauxhall or Warren Street stations.
Waterloo & City: No service.
What other options are there?
Extra river and bus services will be available but TFL have warned alternative transport will be busy. DLR, London Overground, trams and other rail services will be operating as normal.