LONDON (Reuters Life!) - Thousands of workers on London's Underground rail network are to be balloted this week on strike action in a dispute over job security and pay.
A walkout would be the latest in a spate of strikes in recent years that have caused chaos for millions of commuters in the British capital who rely on the sprawling 276-station system.
The National Union of Rail, Maritime and Transport Workers (RMT) said it feared 3,000 jobs could be at risk.
"London Underground seems to think that observing agreements is optional, and its plan to cut jobs is simply unacceptable," said RMT General Secretary Bob Crow.
He said managers had refused to rule out compulsory redundancies, including among staff at the formerly privately owned Metronet maintenance group which became part of Transport for London (TfL), which operates the Underground, last May.
The RMT is also protesting against an "unacceptable" five-year pay offer that it said gave no real-term increase for four years.
Office staff at TfL will be balloted at the same time in a separate disagreement over jobs and pay.
Nearly 10,000 RMT members will be asked to vote in the ballot that opens on Tuesday and closes on April 8.
TfL said it was disappointed at the ballot but added the transfer of Metronet to London Underground had led to the duplication of many roles.
Any job cuts, it noted, would not involve frontline staff working on trains, stations or maintenance.
"There will be no impact on Tube services," it said. "We will be running more services in future, not less."
Reporting by Tim Castle, editing by Paul Casciato