A fresh row over job losses on the Tube has started after unions claimed safety staff were to be cut back.
About 60 posts are to be removed from London Underground's (LU) Health, Safety and Environment directorate.
The Transport Salaried Staffs Association (TSSA) said LU plans to cut the jobs "beggared belief". The Rail Maritime and Transport (RMT) said plans were "a recipe for disaster".
LU said the cuts would not affect those who carry out safety checks.
TSSA general secretary Gerry Doherty said: "It beggars belief.
"This news comes during the inquest into the July bombings five years ago in which the heroism of LU staff has been widely recognised and praised."
Bob Crow, general secretary of the RMT said: "TfL's repeated claims that they would do nothing to compromise safety on the Tube have once again been exposed as totally bogus."
An LU spokesman said the organisation had told unions about the job cuts over a month ago.
"As part of the review announced last month to reduce back office jobs at London Underground by around 800, around 60 posts will be removed from the company's Health, Safety and Environment directorate," he said.
"The posts represent less than a quarter of the directorate's total staff and are non-operational advisory roles, not in those teams which carry out maintenance and safety checks on the railway."
Members of both unions have staged three 24-hour strikes in recent weeks over plans to cut ticket office jobs.
A fourth strike is planned for 29 November. Union leaders have said they have no plans to disrupt services over Christmas and the new year.
Talks at the conciliation service Acas aimed at resolving the dispute were adjourned yesterday and will resume tomorrow.