British minister: UK might quit European rights court

She added: "When Strasbourg constantly moves the goalposts and prevents the deportation of dangerous men like Abu Qatada, we have to ask ourselves, to what end are we signatories to the convention? Are we really limiting human rights abuses in other countries? I'm sceptical. But are we restricting our ability to act in the national interest? Are we conceding that our own Supreme Court is not supreme? I believe we are."

The ECHR caused controversy in the UK last year by blocking the deportation of Qatada, an Islamist preacher, to Jordan for fear it might try him using evidence obtained by torture.

It prompted an earlier uproar by ruling that British prisoners should have the right to vote.

May's speech is seen by British analysts as an appeal to right-wing voters and right-wing politicians in the Conservative Party ahead of 2015 elections.

It comes after a recent surge in popularity by the anti-European UK Independence Party (Ukip).

It also comes after Tory leader David Cameron promised to end British co-operation with EU-level crime-fighting structures, such as the European Arrest warrant, in the island nation's broader decoupling from the European mainland.

Previous Tory hints on quitting the ECHR have attracted criticism from the government's pro-European coalition partners, the Liberal Democrats, and from top jurists.

The British attorney general, Dominic Grieve, last October noted that Belarus, a human rights pariah, is one of the few European states which has stayed out of the convention.

"It would put us in a group of countries that would make very odd bedfellows," he said at the time.

The ECHR itself, which acts as a last recourse for human rights victims, but which struggles to implement its rulings in repressive countries, such as Russia, has also voiced concern that a British exit would harm its work.

Speaking to EUobserver back in 2011, at the time of the prisoner vote dispute, Thorbjorn Jagland, the secretary general of the court's parent institution, the Council of Europe, said a British exit could see other countries follow.

"I think one has to think about the consequences of such an act. It could be the starting point of undermining the whole convention system that we have built up in Europe ... If one country starts to opt out of the convention system and the court, it could be the start of a process that others will follow," he said.