City centres must swap shops for offices, housing and public space if they are to prosper, according to a leading think tank.

The Centre for Cities warns that struggling high streets have too many shops but not enough commercial space for other businesses.

Retail accounts for twice as much space as offices in many city centres but the most successful have more than three times more office space than retail.

In a survey Newport city centre had the highest amount of vacant retail lots at 28% while more than half its commercial space was accounted for by retail premises, followed by Blackpool, Bradford, Wigan and Sheffield.

Those with the lowest proportion of vacant retail lots included Cambridge with just 8%, followed by Brighton, Exeter, London and Worthing.

The think tank says struggling city centres must reduce their reliance on retail and instead focus on creating a better environment for other firms – especially exporting firms in sectors such as ICT, legal services, insurance and marketing.

Andrew Carter, chief executive of Centre for Cities, said: 'We need to reimagine struggling city centres as places where lots of different businesses can locate and create jobs and where lots of people want to go for a variety of reasons.

'This means reducing the reliance on shops, and focusing on creating a more attractive environment for a wider range of firms.'