As a fresh wave of postal strikes started again, union leaders have warned of further disruption as the dispute remains deadlocked. Thousands of members of the Communication Workers Union (CWU) staged a 24-hour stoppage, manning picket lines outside mail centres across the UK in a bitter row over jobs, pay and modernisation. Two further strikes will be held on Friday and Saturday and the leader of the union has warned the action will escalate unless there is a breakthrough. Efforts to resume peace talks collapsed on Wednesday night and CWU leader Billy Hayes said there was "every prospect" industrial action will now be stepped up. The warning raises the threat of huge disruption to Christmas post unless the bitter dispute is resolved soon. The CWU is is still considering whether to take legal action over Royal Mail's move to hire 30,000 agency workers to deal with the backlog of mail caused by the strike as well as the Christmas rush.