The UK government's decision on whether to allow badger culling to curb cattle TB in England is to be delayed.
The Department for Environment, Food and Rural Affairs (Defra) had planned to announce its completed policy around the end of this month.
But BBC News understands it could come as late as May - raising doubts over whether a cull could begin this year.
One source said Defra did not want to "mess up" again after abandoning its plans to sell some public forests.
Defra came under heavy fire over the plans for England and announced on Thursday that it was scrapping them.
The latest government figures suggest that numbers of cows infected with tuberculosis are falling in England and Wales, which campaigners say makes the case for culling more difficult.
Agriculture Minister James Paice told the National Farmers' Union (NFU) conference this week that there would be a delay.
Sources suggest a number of factors make an announcement before May unlikely.
There are practical issues to be sorted out over how farmers would be licensed to conduct the cull - details that may be crucial to the chances of culling reducing bovine TB, and to the government's chances of surviving any legal challenge to its plans.
But one source close to the issue said the department's experience with its plans for the forests were also behind the delay.
"They've messed up on forests - they don't want another one," the source said.
On Thursday, Environment Secretary Caroline Spelman was forced to apologise to MPs over plans to transfer 258,000 hectares of state-owned woodland in England into private management, acknowledging the government had "got this one wrong".
The government launched a consultation on bovine TB management in September, Mr Paice telling reporters: "Bovine TB is having a devastating effect on many farm businesses and families... we can't go on like this."
Before and after the election, he assured farmers that his government would introduce badger culling.
The NFU is keen to see it begin.
But Kevin Pearce, the union's director of regions, told BBC News it was important that the government took time to get the details right.
"Clearly we want a decision as soon as possible, but this has to be done properly,"
"Defra has to consider all of the responses and all of the facts before making any announcement in response to its consultation."
The government's interpretation of the scientific background is that to be effective, culling would have to be done over large areas with as many landowners as possible taking part in a co-ordinated way, and must sustained regularly for five years.
Critics suggest this will not be possible, and that some farmers are likely to drop out if they find they are spending money to hire marksmen without seeing a benefit.
The science suggests that fragmenting the cull in this way would lead to a rise in TB incidence, as badgers scatter from their habitual runs and infect new herds.
The NFU wants groups of landowners to form into collective legal entities and apply for collective licences.
This idea is under discussion, as is what measures the government could use to force farmers to finish the job if they tried to withdraw.
A further issue that Defra wants resolved is security, with the NFU's submission to the consultation acknowledging: "There is concern within the industry that by participating in a cull, farmers and landowners will be targeted by activists wishing to disrupt a cull by damaging property and/or by harassment of farming families".
Delaying the announcement until May could put the chances of beginning to cull this year in jeopardy.
The NFU says it could be done.
But opponents such as the Badger Trust are likely to seek a judicial review, which could mean substantial delays.
And if data continues to indicate a reduction in the numbers of cows contracting TB, that would boost the trust's case that culling is not scientifically merited.
Provisional figures for the first 10 months of 2010 show that for the UK overall, a smaller number of cattle confirmed as TB carriers were slaughtered than during the same period a year earlier - 25,924 compared with 29,243.
England and Wales separately show a similar trend; and this follows a fall between 2008 and 2009.
"If culling had been introduced two years ago, everyone would now be leaping to the conclusion that the reduction was down to culling and saying 'we told you so'," said Badger Trust spokesman Jack Reedy.
"Plainly, what's happened does demonstrate that the disease can be controlled without the necessity of killing wildlife."
The English delay may also have implications for the Welsh Assembly Government, which - in a separate move under a different law - also wants to introduce culling this year.