The Tories and Lib Dems are hoping to drum up enough opposition on Labour's backbenches to halt drink law changes.
Nine out of 10 pubs are thought to have applied for late licences
Ministers have been defending their plans to relax licensing laws saying they will help combat binge drinking.
But in the past few days there has been increasingly vocal opposition to the plans from judges and police.
And Conservative leader Michael Howard said there should be no liberalisation until binge drinking had been brought under control.
Although the legislation has been through parliament, Lib Dem culture spokesman Don Foster said it had yet to be formally put on the statute book.
"If we get enough people voting against it then that's one way of putting it off," he said.
Using a procedure known as "praying", opposition politicians or backbench MPs can try to stop ministers putting an Act into force by putting down a motion to annul - usually through a Commons early day motion (EDM).
If enough MPs sign the EDM it can force a debate.
Tory culture spokesman Theresa May said: "It would be extremely dangerous for the government to press ahead when they have clearly failed to get to grips with the problems of binge drinking.
"We will be using parliamentary procedure to block the legislation when it comes before Parliament."
On Wednesday Licensing Minister James Purnell defended the new licensing laws, saying they would combat binge-drinking and violent crime.
Although pubs will be allowed longer opening hours from November, they will face more stringent controls, he said.
Mr Purnell told the BBC: "What we're trying to put in place is a much tougher set of powers to deal with the minority who do cause problems."
Licensed premises can apply to extend their opening hours beyond 11pm from 24 November, potentially to allow 24-hour drinking in some cases.
But Mr Purnell said the Licensing Act would also enable the authorities to close down pubs more easily, install CCTV, bring in new management or reduce licensing hours.
He added that the Act would be under continuous evaluation, hinting it could be altered if there were problems.
The council of circuit judges, representing 600 judges across England and Wales, said they were "in no doubt" longer opening hours would mean an escalation in violent crime.
Those offences, they said, would include "rape, grievous bodily harm and worse".
Judge Charles Harris QC was particularly critical of the plans, saying a high proportion of British people become "pugnacious and bellicose" after drinking.
He contrasted this to the continental drinking habits, where people "sit quietly chatting away at cafe tables".
Earlier, a report by the Association of Chief Police Officers (Acpo) suggested liberalising licensing laws would create a holiday-resort drinking culture.
The report claimed there was "a strong link between the increase in disorder and the explosion of late-night premises".
"The assertion 11pm closing leads to binge-drinking is simply not supported by the evidence," the report stated.
Nine out of 10 pubs are thought to have applied to stay open an hour or two later - rather than all night as expected.