Post boxes were sealed during wildcat strikes in October

Postal workers had called for two 24-hour walkouts in the city during December as part of a row over pay.

They want the London weighting allowances to be increased to �4,000.

Unofficial stoppages, which started in London, crippled post deliveries in October but ended after the union and Royal Mail agreed to further talks.

'Rely on us'

Dave Ward, deputy general secretary of the Communications Workers Union (CWU), said: "The capital's postmen and women know the public rely on us through the year, but especially at Christmas.

"We're not going to let them down."

Talks between the union and Royal Mail about a deal to scrap second mail deliveries and other changes aimed at boosting productivity continued on Tuesday.

Mr Ward said they were "very close" to reaching an agreement and progress had been made on the London weighting issue.

Previously, Royal Mail had said it would not improve a �300-a-year increase in London Weighting allowances, which took the inner London allowance to �3,784 a year (an increase of 8.6%) and outer London allowances to �2,667 (12.6%).