Hundreds of hunts are expected to ride out today to mark the start of the fox-hunting season in England and Wales, in spite of a ban on hunting with dogs.
About 200 hunts hope to exploit loopholes in the government's Hunting Act, which came into force in February.
Some hunts will take a hawk or other hunting bird with them as a way around the ban which still lets hounds chase and flush out foxes as long as they do not kill them.
The 50 riders of the South Durham Hunt plan to use an eagle at their meet in Prime Minister Tony Blair's constituency of Sedgefield in northeast England.
"According to the regulations you are allowed to put a pack of hounds into a wood, so that the bird can hunt the vermin that comes out the other side, be it fox, grey squirrel or whatever," said Mark Shotton, the South Durham Hunt's master.
Mr Shotton said they had been practising with the bird for a month but feared heavy rain might limit Saturday's activities.
The pro-hunting Countryside Alliance said public support for the ban had fallen to 45 per cent, compared with 63 percent in 1999, citing a specially commissioned survey.
"Hunts are determined to keep going until this pointless and prejudiced legislation is repealed or replaced," said Countryside Alliance Chief Executive Simon Hart.
However, the League Against Cruel Sports says many hunts appear to be breaking the law. It said it had found 157 different allegations of illegal hunting against 79 different hunts since the ban started.
"A significant hard-core of pro-hunting extremists appear to be determined to carry on hunting illegally," said League chief executive Douglas Batchelor.
Last month, the Countryside Alliance lost a key round in its legal battle against the ban when nine Law Lords unanimously ruled against a claim that the Hunting Act was invalid.