Signal workers are in dispute over pay and conditions
|
Talks aimed at averting a strike by Tube workers on New Year's Eve are expected to resume on Thursday.
The Rail Maritime and Transport union (RMT) blamed managers for delaying a crucial meeting on Wednesday.
About 330 signal workers are in a dispute with their bosses over pay, hours and potential job cuts.
Meanwhile, Aslef members have voted to strike on the Piccadilly Line on Christmas Eve and 5 January over a colleague's demotion.
Members' support
Results of an RMT ballot on industrial action will also be announced on Thursday.
The RMT says it is confident its members will support industrial action.
The union's general secretary Bob Crow said he was extremely disappointed with the delay in talks.
But an LU spokesman complained that the union had walked out of earlier negotiations.
Talks to avert that action broke down on Tuesday.