Controls on the supply of alcohol in Scotland - described as devastating, discriminatory and draconian by retailers - will not be forced into law in September.

The Scottish government's proposals, which include a minimum price for alcohol, a ban on promotions and a social responsibility fee, have outraged opposition MSPs who have demanded that the measures should be subject to debate and a vote before becoming law.

The process is likely to delay any changes by at least a year.

Liberal Democrat justice spokesman Robert Brown said: "It is outrageous that the SNP is trying to sneak through such major reforms. We need a considered approach, not stealth and soundbite."

The suggestion that local councils could be given the right to increase the minimum age to purchase alcohol to 21 in c-stores drew particular fire from retailers' representatives. Scottish Grocers Federation chief executive John Drummond said it would "establish ridiculous anomalies between on- and off-sales and penalise the majority of under-21s who drink responsibly.

"It is disappointing the Scottish government has resorted to the use of a gimmick which will have little effect on the problem of underage drinking, rather than looking at sensible measures including better enforcement of current legislation and use of proof-of-age schemes," he added.

ACS chief executive James Lowman said the Scottish government was discriminating against one part of the industry. "It will remain legal for under-21s to buy and consume alcohol, so the proposal will have no impact on drinking among young people," he said. "Instead, this will severely inconvenience customers and retailers. Shop staff will face the repercussions in increased abuse, intimidation and violence from unhappy customers."

Both associations vowed to oppose the "ineffective and harmful" measures.