Off-licences in the London Borough of Bexley have been told by the local licensing officer that they must sign a contract committing them to a Challenge 21 or older policy.
In a letter to all licensed premises in the borough, Diana Kraus says the action is being taken as a matter of policy at the request of the local police and the council's public protection service.
The "acc eptable behaviour contract" on the responsible ret ailing of alcohol will require retailers to operate Challenge 21 schemes, display app ropriate signage and keep a record of challenges.
As part of
their side of the contract the borough and police agree to provide challenge books and notices free
and carry out test purchases.
A council spokesman said: "Although it is only a week since the contract was sent we have already had an encouraging response with approximately 20% of the contracts signed, and contact from other businesses saying that they were considering the proposal.
"There have been no direct refusals. The decision to sign may be taken into account if there are any future problems and considering whether the business is promoting the licensing objectives."