PUBS, clubs and supermarkets applying for permission to sell alcohol will be forced to prove how they will reduce customers' drinking, under proposals by MSPs.

Plans for more new legislation would see local authorities required to put a block on bids by businesses for licences if they cannot demonstrate efforts to "reduce consumption".

But the proposal, buried in the Air Weapons and Licensing (Scotland) Bill, has already been branded unworkable, with businesses having little or no control over their customers' individual choices and how they consume alcohol.

One senior trade source said supermarkets would have to check customers' recycling bins for evidence their drinking was within acceptable limits.

It has also sparked calls for the authorities to instead enforce existing but rarely used legislation which prosecutes premises for selling to intoxicated customers or the adoption of schemes similar to Cardiff where venues that sell clearly drunk members of the public their last drink are named and shamed.

One leading figure involved in the licensing system said: "How do licensing boards reduce consumption? They simply can't.

"If you want to deal with over-consumption you deal with the over-consumers and those who allowed them to over-consume.

"But you can't regulate the amount of alcohol people buy for domestic consumption nor the amount they drink in their homes, even if that was considered desirable."

The Stage One report of the Air Weapons and Licensing Bill recommended a new 'principle' around over-consumption which boards would be required to consider. It would be in addition to the five underpinning current licensing legislation and designed to protect health, children and the general public from alcohol-related nuisance. Boards are also required to have 'over provision' policies to determine which areas are at saturation point when considering new licence bids.

The report states: "Given the overwhelming evidence received of harm and links to disorder from over-consumption, an additional licensing objective should be added to the 2005 Act relating to the reduction of consumption."

Asked how he believed the proposal would pan out in a real setting, Kevin Stewart MSP, convener of Holyrood's Local Government and Regeneration Committee, said a range of witnesses had given evidence on "the increasing impact that over-consumption of alcohol can have".

He added: "Licensing boards should have goals to protect and improve public health and clearly over-consumption of alcohol affects public health greatly. The inclusion of an explicit objective would ensure that all boards must consider public health impacts in the future."

Bill Butler, chairman of Glasgow Licensing Board, the country's biggest, said the proposal emerged without consultation, adding: "We want to know what having a licensing objective on over-consumption would add and how it would be enforced?

"Protecting and promoting health is an existing licensing objective and there is also a range of criminal offences that target drunkenness."

The Wine and Spirit Trade Association, which represents several of the major supermarkets on alcohol issues, said the committee failed to acknowledge falling levels of alcohol consumption, deaths and hospital admissions.

Chief executive Miles Beale also said: "Scotland already has a fifth licensing objective, on health, the application of which has not been evaluated and so its impact is entirely unclear. With clear progress being made and no evidence that the fifth licensing objective is having any impact, it is bemusing that more unworkable objectives are being proposed.

"This will certainly add to the complexity of the licensing system while doing nothing to tackle alcohol related harm."

A spokesman for the Scottish Grocers' Federation said: "There is simply no need for a new licensing objective. The Committee should have realised that, in effect, reducing consumption of alcohol is already covered by the existing health objective."