Thousands of staff at mobile phone giant O2 are taking part in a flexible working initiative as part of the firm's contingency plans for dealing with disruption during the Olympic Games.

A quarter of O2's 12,000-strong UK workforce will work from home, local cafes, O2 stores - in fact anywhere except the office.

O2 said it is believed to be the biggest flexible working scheme ever undertaken, and it has pledged to share the results with other organisations.

The communications firm said it had previously saved more than £3 million in overheads by allowing staff to work "remotely" rather than travel to an office.

O2 business director Ben Dowd said: "We believe a cultural step-change is under way affecting staff and businesses, as work increasingly becomes something we do, rather than a place that we go.

"Today's office-wide flexible working initiative is an opportunity for us to take the next step on our flexible working journey and tangibly demonstrate the opportunity and potential available to British businesses today.

"We practise what we preach, and by asking O2 employees to work together as a team to test the company's flexible working practices for themselves, we want to show that there are no limits - no matter how big or small your business is.

"By sharing experiences from across our business, from business divisions to operations, we hope to encourage more organisations to help their workforce become mobile."

Staff from O2's offices in Slough, Berkshire, will take part in the test.

O2 said two out of five firms believed that staff were more productive if they could work flexibly, but many had policies on the issue which were outdated and ineffective.