A freeze in business rates could give the struggling UK high street chance to reinvent itself for the 21st century, a think-tank has claimed.

And the rise in online shopping is the biggest challenge faced by high street businesses, according to Policy Exchange.

By freezing business rates, it would give the threatened businesses some "breathing space" to turn the situation around, it said.

However, the think-tank acknowledged that not all current high streets will necessarily be able to continue as shopping centres - so, in other words, some areas may be on a commercial downward spiral that can not be reversed.

There has been a marked increase in the number of boarded up shops in recent years, with house streets around the country liberally dotted with signs advertising retail property to let and retail property to buy as the economy has faltered and consumer habits have changed.

Figures released this week suggest that shop vacancies have hit a new high of 11.9%, with a series of high-profile retail downfalls, such as those affecting Jessops and Comet, contributing to the mass of empty units.

Despite the doom and gloom, high streets are said to have been outperforming out-of-town retail parks thanks to an influx of evening diners and drinkers.

But the think-tank points to a four-fold surge in online purchases since 2006 as the big issue for high streets.

Head of housing and planning Alex Morton stressed that the case for a two-year business rates freeze is put forward "in the context of giving breathing space for further changes to retail policy to bring it into the 21st century".

Morton added: "Policy needs to give high streets the best chance to reinvent or renew themselves but it should primarily focus on removing barriers to consumer choice that push up the cost of living, and must not assume all high streets can or should remain as shopping centres."