A government minister has denied the Education Bill was being delayed to allow for further talks with critical Labour backbench MPs.
Labour rebels claim a deal will be struck to allay fears over the bill
Critics of the bill said the government was preparing to make more concessions in order to win their backing.
Home Office minister Hazel Blears, who denied any delay, said the bill was set for publication by the end of February.
The Education White Paper proposes setting up independent "trust" schools, with more say over admissions.
Fears that the government may be forced to rely on the support of the Conservatives to get the legislation through parliament follows embarrassing backbench revolts over ID cards and the Terrorism Bill.
More than 90 Labour backbenchers, fearful this could lead to academic selection "by the back door", have signed up to an alternative version.
Liberal Democrat Education spokesman Edward Davey said any delay should be used to establish further changes to "unfair" school admissions.
He said: "With mounting evidence that the current system already harms the disadvantaged, Labour's plans could make today's social segregation in schools even worse."
But Mr Davey warned ministers not to attempt to avoid publicity by publishing the bill during Parliament's half-term break, which begins on Thursday.
"Backdoor selection is bad enough without it being smuggled in by the back door," he said.
BBC Political Correspondent John Pienaar said: "According to prominent Labour critics, there will have to be a deal.
"Senior Labour rebels say they have been offered one by ministers at the Education department."
The correspondent said they claimed the arrangement involved "a clear indication that councils will be able to build and run new school" and an assurance that "the veto given to the education secretary meant to open the market to businesses and parents will be watered down or removed entirely".
But Ms Blears told BBC News: "We will get a bill and we will get it in the time frame.
"Education is incredibly important to Labour and that is why we want to get it absolutely right."
"What I know about the delay is that there isn't one" she said, adding that there had simply been "healthy debate" in the party.