A planned crackdown on cheap alcohol will not work unless supermarkets are stopped from selling it below cost price, a senior Labour MP has said.
Keith Vaz, chairman of the home affairs committee, called on the government to bring in a minimum price for alcohol in supermarkets to tackle binge drinking.
Home Secretary Jacqui Smith said the government held off from such a move over fears it would harm the economy.
She said it was carrying out further research into alcohol pricing.
Speaking in a debate on Thursday's Queen's Speech, Mr Vaz said he welcomed the government's plans to outlaw "all you can drink" style promotions in pubs and bars.
But unless the government tackled the problem of supermarkets selling alcohol below cost price as a "loss leader" it would not "solve the problem of alcohol-related crime".
The Labour MP said supermarkets were "still selling alcohol too cheaply" and called for the introduction of a "floor price" to stop this.
During its investigation into binge drinking, Mr Vaz's committee was told young people often "pre-load" with cheap alcohol bought in supermarkets before going out to pubs and bars.
Ms Smith told MPs the new mandatory code for "responsible alcohol sales" would cover the off-licence trade as well as pubs and bars.
But she said in the current economic climate, a minimum price for alcohol might not be appropriate and the government wanted to do more research on how it might help tackle binge drinking without impacting disproportionately on others.
She side-stepped the question of the likely impact of the duty rise on beer introduced in the pre-Budget report on traditional pubs, which MPs were told were closing at a rate of 36 a week, saying she could not comment on future tax policy.
The cost of a pint of beer in pubs when Labour came to power 1997 was twice what it was in supermarkets, but it was now seven times higher, MPs were told.
Explaining the planned crackdown on drinks promotions, Ms Smith said people knew how to enjoy alcohol responsibly but there was a minority "who run out of control and ruin it for others".
She pledged: "We will give the police the powers they need to tackle the crime and disorder that stems from excessive drinking.
"We will take tougher action against retailers and bars that sell alcohol to children and ensure the industry plays its part in ending irresponsible promotions, such as 'all you can drink' offers."
Under the legislative package unveiled yesterday, the Policing and Crime Bill will introduce the new code of conduct, along with tighter controls on lap dancing clubs.
Ms Smith said local people would have "more of a say" over whether lap dancing clubs were allowed to open and whether existing licences would be reviewed.
Shadow home secretary Dominic Grieve said the introduction of 24-hour licensing was a "mistake" and asked if there might be greater local discretion over issuing licences.
Ms Smith said the mandatory code would enable there to be "specific conditions, which would relate to all licensed establishments and also include ... probably a larger number of provisions, which could be applied at a local level..."