Britain's anti-terrorism laws have led to serious human rights abuses, Amnesty International has claimed.
New laws have been brought in to deal with the terror threat
The campaign group's report highlights anti-terrorism legislation which has been enacted in the past five years.
It claims new legislation limits the powers of the courts and attempts to reverse the ban on the inadmissibility of evidence obtained by torture.
The lord chancellor said it was unfair to criticise the government's commitment to human rights.
Amnesty's report criticises the now abandoned indefinite detention of foreign terrorism suspects and its replacement with control orders allowing house arrest.
Its report says those subjected to control orders should receive compensation.
The human rights group claims UK authorities have "effectively persecuted" men they have labelled as international terrorists, with devastating consequences for the men and their families.
However, Amnesty says: "It is the international impact of UK measures in relation to torture that is of even greater concern."
The UK is effectively giving a green light to other countries to commit abuses, it adds in the report called UK- human rights: A broken promise.
It says the publication follows meetings between Amnesty International's secretary general Irene Khan and senior UK ministers.
Amnesty says "the UK's attempts to rely on Memorandums of Understanding (MoUs) in deportation cases where people are at risk of torture are a dangerous circumvention of international law."
The group claims the MoUs - which are meant to ensure the deported persons are not tortured - "fail to effect systemic changes in the countries in question that alone can safeguard against torture".
Responding on BBC Radio 4's Today programme, Lord Falconer, the lord chancellor, said: "What Amnesty are doing is in practice disagreeing with us on whether or not the laws are too tough.
"But they should not suggest we are breaking human rights principles because we are complying always with human rights principles."
He added it was "unfortunate that an organisation of Amnesty's standard is in effect attacking our values when what they are really doing is saying you are being too tough in relation to the stances you are taking within human rights law".