Long-term migrants to Britain who are not yet properly registered should be given citizenship, according to the most senior figure in the Catholic Church in England and Wales.
Cardinal Cormac Murphy O'Connor's comments came after Mayor of London Boris Johnson mooted an amnesty for 'illegals' - and was immediately rubbished for doing so by figures in his own Conservative Party, tabloid papers, the Immigration Minister, and the anti-immigration lobby group Migration Watch.
The Cardinal told BBC Radio 4's Sunday programme that many newcomers to the country were vulnerable and needed support. He said there was a responsibility for the country to welcome migrants and to "appreciate the gifts that they bring and also make sure that in some way they are supported".
He continued: "A lot of the people who come are quite vulnerable and can easily be threatened and exploited. But I think also there is a point here about some migrants who come here and are here for years and they are undocumented. After a certain time a way should be given for them to receive citizenship here and so get the benefits of that."
Last week, Mayor of London Boris Johnson announced advisers were studying the potential benefits of an amnesty for the UK's estimated 700,000 'illegal' immigrants.
Johnson said that allowing them to earn the right to stay in Britain would see "hugely increased" tax revenues. Migration Watch has tried to claim the move would be vastly expensive and is making asymmetric comparisons with Italy and Spain.
Immigration Minister Phil Woolas, who recently attacked the work of lawyers and human rights groups in supporting the access of asylum seekers to basic justice, and who dismissed the verdict of the court over an appeal that went against his wishes, has reportedly called Mr Johnson "a naive nincompoop" for his amnesty suggestion.
The remark is reported in the Daily Mail, which gives a good deal of publicity to Migration Watch and its chief protagonist, Sir Andrew Green.
But in addition to the Catholic Cardinal's remarks, the debate around the Mayor's investigations has been welcomed by the religion and society think-tank Ekklesia, and by the Rev Vaughan Jones, a United Reformed Church minister who is director the London-wide agency Praxis.
Mr Jones commented: "It is too easy to dismiss Boris Johnson's call for an amnesty as naive. Amnesties are only one tool to use to deal with significant numbers of migrants who have been made vulnerable by the immigration system. It is more naive to think that it is possible to continue with current policy."
He added: "Governments can talk and act tougher and tougher. But neither the talk nor the action works. Just as our financial order needs a new architecture so do the international approaches to migration and development. An amnesty would only be a small part of human rights policy on migration and the global order. We need to talk about Mayor Johnson's proposals not rubbish them.
He concluded: 'The most important step for those of us who want a just, sustainable migration policy is for government to accept that a migrant is a human being. Once that becomes the given of the debate then we can proceed with discussions about how to honour basic rights. Until then, with or without occasional amnesties a migrant is not a human being in law - and is therefore a commodity."
See also: 'The migration "debate" has lost its humanity,' by Vaughan Jones http://ekklesia.co.uk/node/8059