Fraud busters: Pippa Farrington (right), chief pharmacist at Chelsea and Westminster Hospital, looks at a new leaflet issued as part of a government crackdown on prescription fraud with colleague Caroline Fletcher.

The leaflet explains that from April, patients will be asked to prove that they qualify for free prescriptions when claiming exemption from charges.

The government claims that£150m a year is lost through prescription charge evasion.

It aims to cut this figure by 50 per cent by the end of 2002.

A four-week publicity campaign started on Monday to raise public awareness of the new rules.