David Davis, the shadow Home Secretary and Tory leadership front-runner, said yesterday he would repeal the ID Cards Bill even if it were significantly watered down by Labour rebels.
He said: "Despite ample opportunity, the Government has point-blank refused to address the many concerns over ID cards. Their proposals are illiberal, impractical, expensive, and unworkable. The next Conservative government will repeal any ID card legislation."
His comments are the toughest statement of opposition yet from the Tories, following months of uncertainty over the strength of their opposition to the cards.
Meanwhile, Labour left-wingers said their opposition would grow, despite hints from Charles Clarke, Home Secretary, that the estimated £100 cost of a card might be waived if the scheme was compulsory.
Tony Blair hinted at further concessions yesterday at Prime Minister's Questions. He said: "There are real concerns expressed in different parts of the House. We will listen to those concerns and respond to them."