Liberal Democrats have warned they will fight any attempt to weaken human rights laws by "zealots" in the Government.

Lord Wallace of Tankerness, the party's Lords leader, said he could not comprehend why ministers would want to abolish the Human Rights Act.

"I would rather live in a country where there is such a human rights check over decisions and actions of ministers and the executive than in a country where ministers and the executive can ride roughshod over basic human rights."

Lord Wallace, a former Deputy First Minister, said recent events had thrown into sharp focus the "challenge of balancing liberty and security in an age when terrorism stalks the globe".

But the former advocate general for Scotland said the ability to challenge the Government was "a core part of our liberty and democracy" and must be upheld.

"And yet the Government has made clear their intention to do away with the Human Rights Act and replace it with a British Bill of Rights."

He questioned which rights currently enjoyed by people would be "stripped out" under the proposed change.

"Surely it can't be protection of freedom of speech, or the right to a fair trial, or the right of religion, or freedom of assembly, or the right to a private life."

Perhaps the "real problem" was not with the Act, but the fact that it gave UK citizens a "pathway to the Strasbourg court" and the ability to challenge in Europe a government decision.

"This is a fight," Lord Wallace said. "The contract between the state and the public needs to be retained and enhanced, not diminished or swept aside."

Labour justice spokesman Lord Beecham said: "It is a matter of great regret that there are some who, in their anxiety to distance this country from Europe, misrepresent the impact of the European Convention on Human Rights, the European Court of Human Rights and indeed the Universal Declaration of Human Rights."