Oxfordshire's beleaguered postal service is yet again failing to deliver after being named the fourth worst in the country.

Just 80.6 per cent of first-class mail in the county was delivered the next day in the last financial year, against Royal Mail's national target of 93 per cent.

The league table shows only south-west London, Colchester and Stoke-on-Trent mail delivery was worse.

Last night, Royal Mail blamed the poor performance on the national and local industrial action last summer.

The figures are calculated on 88,500 sample letters, parcels and packets sent nationally every month to 6,000 addresses.

During the second quarter of 2007/08, in which postal workers went on strike, the amount of first-class mail delivered on time in the OX postcode area dropped to just 67.7 per cent.

In the third quarter, that figure rose to 74.8 per cent and again to 92.1 per cent in the final quarter of the year.

Diana Gough, whose late husband Desmond was an Oxford postman for 42 years, said: "I am not surprised it is the fourth worst in the country. I think it is getting even worse, and the deliveries are coming later and later.

The 65-year-old, of Mill Street, Eynsham, added: "It is now very rare to get post before 11am or noon, which is a bad service. They used to stamp the letters with when they were posted, but they do not do that now.

"I have seen no improvement recently whatsoever."

Richard Groves, who runs a mail-order silks firm from Merrivale Square, Oxford, agreed with Oxfordshire's poor ranking.

He said: "This month we had an occasion where we sent something by special delivery which was very important for us.

"It was supposed to be guaranteed to arrive the next day but it was held up in the Leeds office for two days without an explanation.

"Our customer missed a mail order to Italy, so it screwed things up all down the line. We spend a lot of money with the Post Office and we are a little bit trapped."

Najma Hafeez, chairman of the Midlands branch of consumer watchdog Postwatch, said: "Royal Mail's recovery was severely blown off course by last summer's strikes.

"The figures confirm that customers received poor levels of service. Furthermore, the fourth-quarter results show that Royal Mail's recovery from the industrial action was in some respects disappointingly slow."

Royal Mail spokesman Jane Thomas said: "The national industrial action last year, combined with an unofficial dispute in Oxford, damaged services for postal customers in the area.

"However, the 2007-08 report also shows that the performance for first-class mail in Oxfordshire had recovered to 92.1 per cent of mail delivered next day by March 2008."

In January, the Oxford Mail posted 60 first-class letters from across the country and within the city and county.

Only 47 arrived at our Osney Mead offices on time.

Four letters sent from within Oxford were delivered late, beaten by mail posted from as far away as Glasgow.

In 2004, Oxfordshire's first-class post was ranked the worst in the country after just 68 per cent of mail was delivered on time.

According to Postwatch, the county received 19,495 complaints about its service that year.

Last year, a turnaround saw Oxfordshire become one of the best-performing services in Britain, with 93.9 per cent of first-class mail arriving on time.