The move to allow pubs to stay open 24 hours a day needs to be "slowed down" and "given more consideration", the country's top police chief has warned.
All-day opening should curb street brawls, the government hopes
Sir John Stevens told the BBC that if forces had to "man up" the streets when people left pubs around 3am it would take officers away from other duties.
The Metropolitan Police Commissioner, who is to stand down in January, said binge-drinking was a growing problem.
The government is due to overhaul licensing laws next year.
It is hoped permitting pubs and clubs to stay open all day will stagger closing times and avoid drinkers spilling onto the streets at the same time.
But Sir John said such a move would take resources away from other areas of policing, as officers will be diverted to manning the streets in the early hours.
"The fact that
large groups of people will be coming out at 3am or 4am will mean that we have
to man up the streets to deliver a service to ensure these people behave."
He also said binge-drinking was a growing problem.
"I think there has been a deterioration in how people behave on the streets," he said.
"You can see excessive drinking in extraordinary amounts on a Friday or Saturday night. That's one of the reasons I think that assaults against the
police have gone up.
The number of assaults on police officers in London had risen 40% this year, he said.
This was also partly because they have become more "proactive", with 30,000 more arrests this year than two years ago.
The government's Licensing Act 2003 - due to be introduced next year - will give local authorities, and not magistrates, the power grant licences.
Not only will it allow round-the-clock drinking, but it will combine alcohol and entertainment licences into a single licence.
Local authorities will also get discretion to apply flexible opening hours.
And the bill aims to combat drink-related disorder.
Police will have new powers to close any licensed premises without notice for up to 24 hours if there are problems with disorder or noise nuisance.
Culture Secretary Tessa Jowell has said the bill will treat people "like grown-ups" and give the current laws a much-needed overhaul.
In the BBC interview, Sir John also reiterated earlier comments calling for the law on protecting yourself against an intruder to be clarified.
He said there needed to be a "presumption of innocence" on anyone who injures an intruder defending their home.
But the biggest challenge - and frustration - facing police was the threat of terrorism, he added.
"The effort that has gone on since 11 September has been absolutely considerable," he said.
"It is something that we have been very successful on."
But, he said, their successes could not be publicised or were not always reflected in the press, so officers were not always given credit where credit was due.
He also told how he had changed his mind on the government's plan to introduce ID cards.
He said he had become convinced that being able to be certain of people's identity was now essential.
Sir John also said there had to be a balance between protecting the country and protecting human rights.
"I want to make it absolutely clear that some of the laws that have been introduced have been absolutely essential to safeguarding this country," he said.