A POSTAL workers' union is threatening to take strike action in the run up to Christmas.

A letter sent to members of the Communication Workers Union this week warns of possible disruption during the busiest time of the year for Royal Mail, according to reports.

The letter, signed by general secretary Billy Hayes and his deputy Dave Ward, says the union wants a strike-free Christmas and New Year, but it is dependent on Royal Mail sticking to terms of a recent agreement.

CWU had agreed a truce with Royal Mail earlier this month and promised postal workers would be working over Christmas.