Rome  - Italian lawmakers rejected a bid Wednesday to triple the amount of time illegal immigrants can be detained in holding centres, in a rare defeat for Prime Minister Silvio Berlusconi's ruling coalition.

In a narrow vote, opposition deputies - joined by some members of Berlusconi's own conservative coalition - voted against extending the period from two months to six months.

The opposition amendment to a government security decree containing the provision won approval with 232 votes for and 225 against, in parliament's lower-house Chamber of Deputies. There were 12 abstentions.

"I am incensed," Interior Minister Roberto Maroni, one of the strongest proponents of the measure, said after the vote.

It amounted "to an amnesty for illegal immigrants and represents an irresistable call for more landings," on Italy's shores by those making clandestine crossings of the Mediterranean from North Africa, Maroni said.

The current limit of two months in which migrants can be detained at reception camps is insufficient to allow proper identification, which according to Maroni, is necessary to pave the way for their repatriation.

Maroni is a member of the anti-immigration Northern League, a party which says current procedures allow illegal immigrants to pass off as refugees eligible for asylum, thus avoiding expulsion from Italy.

Observers noted that in Wednesday's secret ballot at least 17 members of Berlusconi's conservative coalition must have voted in favour of the amendment which was tabled by the centre-left Democratic Party and centrist Catholics of the Union of Christian Democrats (UDC).

Government measures aimed at curbing illegal immigration including the prolonged detention of people in holding camps, has drawn criticism from the Catholic Church and human rights groups.

Earlier this year on the southern islet of Lampedusa, local residents joined would-be immigrants who had broken out from an overcrowded camp, to protest the government decision not to transfer migrants to other facilities elsewhere in Italy.

In Italy government decrees become effective immediately, but to remain in force for more than a few months they need to be approved by parliament. (dpa)