Accountancy firm KPMG is to offer its 10,000 employees a London Underground pre-pay Oyster card this month to encourage staff to opt for the tube rather than using environmentally damaging cars and taxis.

The firm has revealed that its worst culprits are employees travelling between its Canary Wharf office and the City based offices, where the temptation to jump in a cab for the short journey is particularly high.

Sara Turner, reward manager at KPMG explained: "In London we wanted to focus on the people that are just using taxis to get around, when really they could be helping the environment by using the underground."

To communicate the new initiative to staff KPMG has sent via an email with visual images†that gives details of the scheme and also statistics on the environment and the damaging effects that taking cars and taxis can have.

"So far employees appear to have received the idea quite well, they are impressed and see it as a positive step for the environment by the firm," said Turner.

KPMG will have to cover the £3 deposit charge for each employee that wants an Oyster card.