A planned strike by subway workers in London threatens to disrupt travel on New Year's Eve in the British capital.

Union officials called the 24-hour walkout, set to begin at noon Saturday, to protest new staff assignment and work schedules they say will undermine the safety of the traveling public.

Management is calling on labor leaders to return to the negotiating table to discuss outstanding issues. But the unions insist on a suspension of the planned changes before talks can get under way.

The subway system had planned to offer free transport to all travelers from 11:45 pm on New Year's Eve to 4:30 am Sunday to help revelers get home safely.

The union has called another 24-hour strike January 8 and 9.

Some information for this report provided by AFP and AP.