Calderoli (Northern League) is defending the immigration policy of the last centre-right government (with the Northern League's Roberto Maroni as Interior Minister). One of the characteristics of this policy, which attracted a lot of criticism, was to apply the policy "respingimenti" at sea (as set out under the Fini-Bossi immigration law, if I'm not mistaken). The Italian authorities (coastguards, Finance Police etc) were authorised to intercept boatloads of would-be immigrants (usually from north Africa, but often including migrants from sub-Saharan Africa and even from Asia, I believe) while still at sea, in the Mediterranean (but in Italian waters, I believe), and force them to turn back to their port of origin (in Libya, Tunisia etc), on the basis that they were all de facto "illegal immigrants", without taking any details of the people on board, and, crucially, without establishing whether there was anyone aboard who intended to claim political asylum in Italy, or who might have bona fide refugee status.
In translating this term, I usually found (and find) that it was necessary to use a verb, rather than a noun: to turn migrants back at sea. Thus: "(the policy/practice of) turning migrants back at sea". I'm sure "repel" also works. Speciously (speciousness which is typical of a man who brings the trade of dentistry into some disrepute, one feels), Calderoli is claiming the Vatican has a similar law. But we are hardly comparing like with like here. For a start, nobody is likely to die of thirst, starvation or exposure after being "turned back" after trying to duck behind an exhibit in the Musei Vaticani. Also, I don't believe the Vatican is a signatory to international treaties or charters granting an automatic right to apply for asylum.
"I'm sorry, I'm a stranger here to myself" -- Anon.