Downing Street has signalled it will bow to pressure over MPs' demands for a ban on the use of wild animals in circuses.
But there are still "unavoidable legal difficulties" that must be overcome before the practice can be outlawed, officials have insisted.
Ministers have steadfastly opposed the move fearing the Government will be left open to lawsuits from circus owners and workers. MPs agreed, however, to direct the coalition to introduce a ban from July next year after a debate in the Commons.
Although the decision is not binding, it is highly embarrassing for the Government and has heaped pressure on ministers to act. A Downing Street source said: "The Government will recognise the will of the House."
Tory Mark Pritchard, who led the backbench call for a ban, claimed he had been threatened by the Prime Minister's office unless he backed down.
In an open show of defiance, Wrekin MP Mr Pritchard told MPs he was first offered "incentive and reward" if he complied with the wishes of the party hierarchy but as he stood firm pressure was "ratcheted up" on him.
He said: "I had a call from the Prime Minister's office directly and I was told that, unless I withdraw this motion, the Prime Minister himself said he would look upon it very dimly indeed."
Mr Pritchard said: "I will not be bullied by any other whips. This is an issue I have campaigned on for many years."
There are currently three travelling circuses in the UK, with a total of 39 wild animals, including zebras, lions, tigers and camels. Agriculture minister Jim Paice said Government lawyers advised that it was "highly likely" ministers would be challenged on the basis that an outright ban was "disproportionate in terms of improving welfare in circuses".
A Department for Environment, Food and Rural Affairs spokeswoman said: "The Government will listen to the view of the House and is sympathetic to the motion for a ban. We will continue to look carefully at how this could be introduced, but there are unavoidable legal difficulties that we cannot ignore."