Transport for London warns of Boxing Day Tube strike disruption
Tube services could face severe disruption but there will be more buses on Boxing Day as hundreds of drivers go on strike, Transport for London said.
Members of Aslef union will walk out for 24 hours in a row over bank holiday pay, a dispute over a 1992 agreement.
TfL said there would be extra buses for shoppers heading for the West End or Westfield shopping centres.
It will be the third successive walkout by Tube drivers on the first day of the post-Christmas sale.
Aslef said its members had voted by 9-1 in favour of strikes in a long-running row over extra pay for working on bank holidays.
TfL said almost all the lines were expected to have a reduced and partial service and urged passengers to check before travelling. There will be no services on London Overground.
But 700 bus routes in the capital will operate a Sunday service, and extra buses will be on the routes bound for the West End or Westfield shopping centres in Stratford and White City.
The congestion charge for vehicles entering central London will not apply during the festive period and there will also be no parking charges on roads in Westminster.
Howard Collins, London Underground's chief operating officer, criticised the union for demanding to be paid "twice for the same work".
"The scandalous actions of the ASLEF leadership are an attempt to hold Londoners to ransom, and demonstrate a wholesale disregard for our customers," he said.
"We will be running as many services as possible, supported by London's 700 bus routes, but there will be disruption."