These postal workers were in defiant mood – they had been on strike for two weeks and they wanted to stay on strike.

They are pictured at Cowley parish hall in Between Towns Road, Oxford, in 1971 being addressed by John Mahoney, a member of the postal union executive.

They and their fellow workers had walked out in support of a 15-20 per cent pay rise.

The strike had begun on January 20 and lasted for seven weeks, finally ending in an agreement on March 4.

During the stoppage, the public had had to contend not only without post but with the switch to decimal currency. When the strike ended, staff formed a group outside St Aldate’s post office and walked in “as solid and united as when we walked out”.

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For several weeks after the stoppage, Oxford’s head postmaster Sam Coates urged the public to post only essential letters as staff struggled to clear a huge backlog.

During the strike, many private enterprises were set up to deliver letters and parcels, including one in Oxford. Four housewives established the Oxford Postal and Courier Service in an empty shop in High Street, doing all the delivering themselves.

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They charged 10 shillings (50p) to deliver a letter to inner London and six shillings (30p) to provincial towns with a population of at least 50,000. Other enterprising individuals included chef Charles Lacey, of Chiselhampton, and rowing coach Sir Herbert Thompson, of Haddenham. Mr Lacey delivered letters for between a shilling and 1s 3d (5p and 6½p) while Sir Herbert delivered letters on his bike.