Lawyers have filed papers in the High Court in London seeking judicial review of the use of the Parliament Act to pass a Bill banning hunting with dogs last night.
The bid to overturn the ban is based on claims that the 1949 Parliament Act used to force it through was invalid.
Earlier today, Lord Donaldson, a former Master of the Rolls and one of Britain's most senior retired judges, said in a radio interview the case against the move was extremely strong.
Last night, the Speaker of the House of Commons invoked the Parliament Act to force the legislation through, despite the continued opposition of the House of Lords.
It was only the fourth time in the past half century that the Act had been invoked.
A previous Act of 1911 had only been used three times - including forcing through the current legislation.
The Government of Ireland Act of 1914 (Home Rule) was passed under the 1911 Act.
Fox hunters have pledged to oppose the ban through widespread civil disobedience.
Earlier, British MPs backed a compromise move to delay a fox hunting ban until the end of July 2006. The amendment was passed by 283 to 132, although it was later rejected by the House of Lords.
