* Opposition parties say government let in too many migrants
* Poll says 46 pct of Italians see migrants as risk
* Government has to retreat over citizenship law
By Crispian Balmer
ROME, Sept 13 (Reuters) - Rape allegations levelled against foreigners are fuelling anti-immigrant sentiment in Italy ahead of elections due early next year, when migration is likely to top the political agenda.
Anti-immigration politicians have leapt on the crimes to ram home their message that the centre-left government has been lax on border controls, allowing more than 600,000 migrants, mainly Africans, to enter the country over the past four years.
"There are too many of them. I will send quite a few home," Matteo Salvini, the head of the rightist Northern League, wrote on Twitter this week after police said a Bangladeshi man had been arrested in Rome on suspicion of raping a Finnish au pair.
The Rome case came two weeks after a young Polish tourist said she was gang raped by four Africans, three of them aged under 18, on a beach in the Adriatic resort of Rimini.
The woman's partner was badly beaten by the youths and a Peruvian transsexual said she was raped and assaulted by the same quartet later the same night.
The leader of the gang was named as a Congolese asylum-seeker who had been allowed to stay in Italy on humanitarian grounds. The other three were Moroccan brothers aged 15 and 17, who were born in Italy, and a 16-year-old Nigerian.
"A gang of Maghreb worms," said Georgia Meloni, head of the rightist Brothers of Italy party, which is expected to be allied with the Northern League and Silvio Berlusconi's Forza Italia (Go Italy!) party at the election.
An opinion poll in la Repubblica newspaper on Wednesday showed 46 percent of Italians thought migrants represented a threat to their personal safety and to public order against 40 percent in the last such survey in February.
Five years ago the figure stood at just 26 percent.
Opposition parties say the government cannot ignore the issue, pointing to official data showing that in the first seven months of the year 1,534 Italians were arrested or accused of rape compared with 904 foreigners suspected of the same crime.
"Some 40 percent of rapes are being committed by foreigners who make up 8 percent of the population. You can't sweep this under a carpet," said Deborah Bergamini, a lawmaker with Forza Italia. "The influx of migrants is having major consequences."
Though Italy was a colonial power in Africa in the 19th and 20th centuries and migrants have come to Italy for decades, the country mainly served as a transit route for the rest of Europe and so remains an overwhelmingly white country.
However, EU migration policy means that increasing numbers of would-be asylum seekers are having to stay to secure residency permits, meaning many more Africans and refugees from the Middle East are trying to make Italy their home.
Rising public concern over the inflows is starting to affect government policy-making, with the ruling centre-left Democratic Party on Tuesday freezing a long-promised bill that would have granted citizenship to the children of immigrants.
Some 70 percent of Italians backed the measure earlier this year, but support has now plummeted to just 52 percent, according to the la Repubblica survey.
Interior Minister Marco Minniti has also intervened to stem the flow of migrants.
"I feared for democracy in this country," Minniti said last month, explaining why, after months of a de-facto, open-door policy, the government finally introduced measures aimed at preventing people from leaving Libya for Italy.
Over the past 2-1/2 months, the number of migrants reaching Italy has fallen 70 percent from the same period a year ago to some 16,500, but the rape cases have ensured that media headlines have remained highly negative about the newcomers.
German media were accused last year of initially ignoring allegations of sex assaults by migrants at New Year festivities in Cologne in order not to fuel anti-foreigner sentiment. The Italian media has no such hesitancy.
"First poverty, now they bring us disease," a front page headline in Libero daily said this month when an Italian child died of malaria just days after she had shared a hospital ward with two African children suffering the same illness.
Malaria is transmitted by mosquitoes and cannot be passed person-to-person. It was eradicated from Italy in 1970 and doctors do not know how the girl, who had never been abroad, caught the disease.
Cecile Kashetu Kyenge, a Congolese-born European parliamentarian with the ruling Democratic Party, says those sorts of headlines show how racism is on the rise.
"The newspapers turn migrants into the enemies of Italy and people start to believe this nonsense," said Kyenge, a former minister who receives regular racist abuse on social media.
"Racism is used as a political weapon and the situation is getting worse. The problem is we are living in a perpetual election campaign and politicians play on peoples' fears."
The Northern League has led the anti-migrant charge with its leader, Salvini, regularly denouncing migrants on Facebook. The party has been rewarded by a jump in support from 6 percent in 2014 to more than 15 percent today, making it the third largest political force in Italy in many opinion polls.
"The rise of the Northern League can be put down to the party's anti-migrant stance and Salvini's undoubted ability to play the populist card," said pollster Renato Mannheimer. He predicted that the issue would continue to predominate.
"The economy is a much more important issue, but sadly I think it will take a back seat to immigration in the coming election campaign," he said.
(Reporting by Crispian Balmer; Editing by Robin Pomeroy)
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