The unofficial postal strike is set to come to an end with both sides agreeing to meet at conciliation service ACAS.

Postal workers were returning to work today although some strikers could yet refused to accept the terms of the deal.

An agreement was reached in the early hours of Monday morning after a marathon session of talks eventually led to a breakthrough.

Bosses pledged not to take action against employees for going on strike, although some staff accused of intimidation could be threatened with disciplinary measures.

Senior negotiators from the Royal Mail and the Communication Workers Union began a fresh round of discussions on Sunday with the wildcat industrial action threatening to cause more damage to the economy this week.

But the aim to get the thousands of striking staff back to work as quickly as possible ahead of more detailed ACAS talks was achieved.

The strike spread around the country last week after workers in London left work over a pay and conditions dispute and managers sought to pass the job of sorting the Capital's mail on to regional depots.

Trade secretary Patricia Hewitt had called on both sides to resolve the dispute as quickly as possible.

And deputy prime minister John Prescott said on Sunday that postal workers "had to accept modernisation".