Sainsbury's has had more problems with its online set-up, with its main web site unavailable for more than an hour today.

The retailer’s site was down from 12.45pm to 2.10pm and during that period visitors were unable to see the homepage at all. It is the second time in a month part of the web site has been unavailable.

A Sainsbury's spokeswoman blamed the glitch on a power outage at the company hosting the retailer’s web site.

The outage follows the news last month of an IT problem on Sainsbury's online shopping web site which affected some 10,000 orders and caused estimated losses of up to £1.5m in sales.

Sainsbury’s main web site and the home delivery operation are hosted by separate companies.