The government is delaying the publication of a major report on per-pupil funding to avoid losing support ahead of the general election, campaigners have alleged.
Headteachers and local authorities anxiously awaiting the results of a PricewaterhouseCoopers (PWC) enquiry into the inequalities in spending around the country now believe promised reforms are under threat.
The lack of information on what has happened to the report has "created an atmosphere of uncertainty", F40, the association representing the worst-funded local authorities, has said.
The Department for Children, Schools and Families (DCSF) commissioned the report into the Dedicated School Grant in 2008 to help it devise a new formula for how it would distribute education spending from next year.
Civil servants are keen to iron out growing regional differences, which have seen some inner-city councils receiving twice as much money per pupil as other often rural shire counties.
But, despite hundreds of pages of evidence being collected by the PWC team, officials at the DCSF have yet to announce their decision - despite ministers and Gordon Brown promising it would be finalised "early in the new year".
The delay means it is unlikely the consultation period would be finished by a general election, which has to be held by early June. The proposals are likely to be then further delayed or changed by a new government.
"There could be something unpleasant in this review: some areas might gain while others lose out," said Ivan Ould, chair of the F40 group. "There could be things which are an electoral liability.
"It's going to be a really tight election with possibly a hung Parliament. The current government is going to want to hold in abeyance any bad news. They are not going to want to put out anything which will upset people."
Malcolm Trobe, policy director of the Association of School and College Leaders, said he was also "concerned" by the delay.
"Our initial understanding was that it would be released in early January or at least by February, and the fact details have not been released means the likelihood of anything being done before a general election is small," he said.
"We are very disappointed we have not seen the proposals yet," he added.
A decision on changes to the dedicated schools grant has to be made this year before budgets are allocated for 2011-2014.
Currently the grant consists of a basic amount per pupil, plus three additions to compensate for local area differences, deprivation and scarcity of schools. Local authorities that do not qualify for high levels of funding for the three additions get money taken off their per-pupil amount.
Unions and the F40 group say they are impressed with the "robust" PWC evidence. It has information on changing to a system where schools are paid for the activities they run, as well as on how to fund different regions and "high cost" pupils.
A DCSF spokesman gave no reason for the delay to The TES, but said details were being "finalised".
"We are looking at all the issues to see what proposals we can put forward," he said.