The Tories have accused the government of trying to "spin" crime figures to make it look as if the shake-up in pub opening hours has helped cut violence.
Police detaining a woman
Newly-released Home Office figures show violent crime recorded in England and Wales fell 11% at the end of 2005, despite longer opening hours coming in.
But the Conservatives say the figures are "bogus" because this period coincided with a £2.5m policing boost.
Ministers deny "spinning" the figures to make the policy appear a success.
Shadow home secretary David Davis said: "What this shows is that if you put more bobbies on the street you will cut crime.
"However these figures are a result of a six-week crackdown on violence which cost £2.5m - what happens when this money runs out?"
He added: "The government should not use these bogus, inappropriate and spun statistics to justify its 24-hour drinking proposals, especially just after the Home Secretary admitted how concerned he was that Government crime statistics were confusing.
"They should wait and assess the effect of longer drinking hours over a 12-month period at least."
But Culture Minister James Purnell told BBC News: "We did not spin these figures to say that they meant that any conclusions could be drawn about the Licensing Act. That's absolutely clear -- all the way through.
"What we're saying is that it's far too early to make any decisions about what this data shows. We will assess it over months and years."
The Home Office gave the police and trading standards departments £2.5m to target binge drinking between 12 November and Christmas.
With more officers on the streets at night, violent crime went down by 11% overall compared with the same period in 2004, with a 21% fall in more serious types of offence, the figures show.
The figures are the first since licensing laws were changed in November to allow extended drinking hours.
Half of all violent crime is linked to excessive drinking and the government had been waiting to see how the figures would be affected by longer opening hours for pubs and clubs.
Earlier on Wednesday, Home Secretary Charles Clarke said the figures represented a step forward in removing "unacceptable" behaviour from Britain's streets.
In a statement, he said progress had been made on cutting sales of alcohol to under-18s and it was the government's intention to eliminate the problem altogether.
Mr Clarke said police work would continue to drive home the message that the "drunken behaviour of the minority" would not be allowed to "impact the lives of the decent majority of people who enjoy a sensible drink with family and friends".
Mark Hastings, of the British Beer and Pub Association, said the figures showed the combination of flexible opening hours and law enforcement was having a "positive impact".
He said: "Communities are seeing a reduction in violent crime and the pub trade is seeing positive changes in drinking patterns and behaviour.
"The projections of government and the industry have proved far closer to the truth than the prophesies of the peddlers of doom and gloom."
BBC crime correspondent Neil Bennett said it was not possible to draw firm conclusions about the effects of extended opening hours from these figures alone.
He said: "The extra money to tackle drink-related violence has now run out and - as the figures for mugging showed recently - when specially targeted operations stop, so crime tends to go up again."
When the new licensing laws came in on 24 November, police forces said the full implications would not be clear for at least six months.