At the other end of the scale, Gloucester was the unluckiest

The city replaced Salisbury, Wiltshire, which slipped to eighth place after commanding the top position last year.

At the other end of the league table, Gloucester was the unluckiest after being fifth luckiest in 2004/05.

The study was based on the top 120 postcodes in the UK, of which 11 are in the South West.

Bristol was the second luckiest, up one place from the previous year.

Equal chance

Premium Bonds manager Sally Swait said: "Congratulations to Bath, though every Premium Bond in the South West has an equal chance of winning a prize.

"While some places like Bath and Bristol have been luckier than others in the past year, there is no reason why places like Dorchester and Gloucester won't be the luckiest next year."

In the South West, nearly 2.4m people hold Premium Bonds worth over �3.5bn.

But more than 25,000 prizes worth about �1.5m remain unclaimed. There is no time limit on claiming prizes.