12/14/2011 01:35 EST | Updated 02/13/2012 05:12 EST

UK subway workers plan to strike day after Christmas, a busy shopping day

LONDON - London subway workers say they will stage four strikes — including one the day after Christmas — due to a dispute over holiday pay.

The Aslef union says its members will walk out on Dec. 26 — one of the busiest shopping days in Britain — after failing to agree to wages for working the day after Christmas, known here as Boxing Day.

It says union members also will stage 24-hour strikes on Jan. 16, Feb. 3 and Feb 13.

The union said Wednesday that it seeks "adequate" compensation for working on Boxing Day but has not received offers for extra pay.

The London Underground's management says the unions' "outrageous" demand for triple pay and a day off in lieu of working Boxing Day went against an earlier agreement.