Cannabis drive

Sir: I am not in principle against legalising cannabis. But does it impair
the ability to drive? Does it show up on a breathalyser? Is there an
alternative that the police can use? Until these questions are addressed
the answer has to remain no to legalising it.

Mrs Jackie Flaherty
Woldingham, Surrey

Sir: It appears that the most effective way to change the law is with the
assistance of supermarkets, as with Sunday trading and the Net Book
Agreement. Perhaps Tesco or Sainsbury could join the campaign to
decriminalise marijuana by selling it alongside herbs and spices.

Claire Bezzano, Manchester