A fifth of shops are empty in key West shopping centres – and experts are warning of a bleak future.

The latest study on shop vacancy rates published yesterday shows continuing problems at a time when some major retailers are struggling.

However there was also a postcode lottery, with some of the area’s centres ranked among the healthiest in the country.

The study by Local Data Company found Gloucester had a vacancy rate of 22.3 per cent, up 1.7 per cent in six months, with Bristol at 22.1 per cent, up 0.7 per cent.

The South West’s top five centres in the list of those with most vacant stores – among those with more than 50 units – are Swindon old town (19.7 per cent), Bedminster, Bristol (19.3) and Weston-super-Mare (18.6).

However, some of the West’s smaller shopping centres are among the best performing in the UK, with Winton, Dorset, ranked fourth with just one per cent, and Bridport in sixth with 1.6 per cent.

Street, with 3.9 per cent of shops empty, Sherborne (4.6) and Swanage, Dorset, (5.4) are all performing far better than the UK average of 14.3 per cent.

The Local Data Company reports wide differences across the nation, from 36.4 per cent for Leigh Park, Portsmouth, to just 0.4 per cent in Stanmore, North London.

The study says while prime centre ‘core’ areas remain relatively healthy, secondary centres and outlying areas are struggling: “The future looks bleak as consumer spend moves increasingly away from the High Street.”

It says last year saw the disappearance of well-known names from the High Street, including shoe shop Barratts, Focus DIY, gift chain Hawkin’s Bazaar and discount retailer TJ Hughes.

And 2012 started badly with Peacocks falling into administration with 700 stores affected, and problems piling up for PastTimes, La Senza and Blacks Leisure.

Liz Peace, of the British Property Federation, said while some high streets were thriving, others were locked in a spiral of decline.

Prime Minister David Cameron asked TV retail expert Mary Portas to report on how to prevent shopping centres from becoming ghost towns.

The star of Mary Queen of Shops made a series of proposals, and the Government announced a competition for 12 towns to share £1 million to turn around their high streets.

Swindon is among the towns to launch a bid, with public and private bodies joining forces to argue for a pilot scheme.