The Rail Maritime and Transport union says members who work as cleaners for two contractors will not work from early Thursday to Saturday. It said that means no cleaners will be working in the part of the subway, or Tube, near the Olympic Park.
Picket lines will be set up outside several Tube stations, including Stratford, the main stop for the Olympic Park.
General secretary Bob Crow said the strike was to protest the "minimum pay rates" that transport cleaners are paid.
