The law lords dealt a blow to the government's asylum clampdown yesterday by ruling that people could seek sanctuary in Britain by arguing that they feared religious persecution.
The court of appeal in 2002 had ruled that only evidence of torture could be used to stop asylum seekers being deported from Britain.
The only grounds for asylum, according to that judgment, would be a real risk of physical ill treatment.
It meant asylum seekers would be denied the protection of a range of human rights such as a right to worship, right to a fair trial, and freedom from slavery.
Yesterday five law lords in a unanimous decision struck down the appeal court ruling in a judgment that was hailed as historic.
The government took the case so seriously that the attorney general, Lord Goldsmith, argued its case in person. The case was brought on behalf of an Ahmadi preacher from Pakistan, who claimed he would be stopped from practising his religion by Islamic fundamentalists if he were deported, and a Vietnamese Roman Catholic, who claimed she feared persecution because of her faith.
The ruling increases the chances of thousands of people staying in Britain who are fighting deportation to live under a regime they say would breach their human rights.
But the lords ruled the two people who brought the claim did not have evidence to show serious risk of religious persecution, so denied their claim to remain in Britain.
Lawyers and campaigners had feared the appeal court ruling would mean people seeking sanctuary for human rights abuses would not even have their cases considered by asylum adjudicators. Now asylum seekers will have the same protection under the European convention on human rights once they are in the UK, as do British citizens.
In the ruling, Lord Steyn said: "Imagine a case of intended expulsion to a country in which the rule of law is flagrantly flouted, and there is a real risk that the individual may face arbitrary detention for many years ...
"Assuming there is no evidence of the risk of torture or inhuman treatment, is the applicant for relief to be told that the ECHR offers in principle no possibility of protection in such extreme cases?"
Eric Metcalfe of the group Justice said: "The ruling recognises that, in immigration cases, there is more to human rights than just the right not to be tortured."
The Home Office said: "We are pleased the House of Lords has agreed with the court of appeal that these cases should be dismissed. Although the House of Lords has taken a less restrictive view of when a breach of ECHR rights abroad might make removal unlawful, their interpretation is unlikely to make much difference in practice."