Trials of the repellant have been carried out in the South West.

Now it is being offered to postmen and women in Peterborough, in an attempt to prevent them from being attacked by dogs as they carry out their rounds.

Psychological harm

Each year, there are around 5,000 attacks by dogs on postal staff, with 600 workers having to take sick leave.

Safe from harm: A postman on his round

The Post Office estimated that attacks by dogs led to 4,500 working days being lost last year.

The Communication Workers Union (CWU) says that most delivery workers are attacked at least once in their careers, often leading to long-term psychological harm.

A Post Office spokesman said: "It is something we take very seriously, and we want to do everything we can to help postmen and women go about their work safely."

Hipster coats

Another development for postal workers across the country is the introduction of new uniforms.

The Royal Mail is spending £50m on the uniform, which includes items ranging from caps to zip-up hipster coats with detachable fleece liners.

It has the biggest uniformed workforce in the country at 143,000, and will introduce the new uniforms over the next two years.

They will be brought in first in Northern Ireland next month, followed by London and the South East, then the rest of the country by early 2001.

Members of the CWU voted in favour of the new uniforms - the first new design for more than a decade.