Four market traders, who were told in the High Court last week they could not sell their goods in pounds and ounces, have taken their fight to the House of Lords.

Lawyers representing Stephen Thoburn, from Sunderland, and who are also acting on behalf of Colin Hunt, from Hackney, and Cornwall traders John Dove and Julian Harman, yesterday lodged a petition for leave to appeal.

They should learn within eight weeks whether they can make a final bid to reverse their criminal convictions for dealing in imperial measures.

Neil Herron, spokesman for the Metric Martyr Defence Fund, said: "We have to take the fight forward. This is the final domestic legal avenue that we have.

"What we are doing is of massive constitutional significance. We have four men who still have criminal convictions against their name.

"Everyone knows that the decision in the High Court was wrong - the customers know and so do the public.

"We believe the judgement was seriously flawed. What the judge has done is create a hierarchy of statutes."

Mr Herron, standing by the Churchill statue in Parliament Square, London, before handing in the petition at the House of Lords, said: "There are many men and women who fought and died to protect the right of what we are doing today.

"The Metric Martyrs have exposed exactly what their elected representatives have done in their name and without their consent.

"We are not going to let the politicians over-ride the will of the people."