STRIKES by postal workers could escalate into longer walkouts after the collapse of talks aimed at resolving the bitter mail dispute, a union leader warned today.

Billy Hayes, general secretary of the Communication Workers Union, said there was "every prospect" that industrial action will now be stepped up.

Mr Hayes also revealed that the union was close to making a decision on 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.

The warning came at the start of a fresh wave of strikes which will cause huge disruption to mail delivered for the second time this month.

Picket lines were mounted outside mail centres across the UK, with workers said to be "solidly supporting" the walkouts.