The fight against illegal immigration has risen to one of the top campaign themes in Sunday's parliamentary elections pitting Prime Minister Jose Luis Rodriguez Zapatero's Socialists against the conservative PP headed by Mariano Rajoy.

Adriano, a 45-year-old undocumented immigrant from Angola, passes frequently through a Madrid bus station, always feeling nervous about the police officers standing around with their big dog.

"They have not asked me to show my identity documents yet," says the man, who is studying to become an electrician while trying to legalise his situation in Spain.

"But if the PP (Popular Party) wins Sunday's elections, I'm not going to take the bus any more," Adriano sighs. "If the right takes power, things may get bad for people like me."

The fight against illegal immigration has risen to one of the top campaign themes in Sunday's parliamentary elections pitting Prime Minister Jose Luis Rodriguez Zapatero's Socialists against the conservative PP headed by Mariano Rajoy.

Despite there being few outward signs that Spaniards are strongly rejecting the increasing presence of immigrants in the country, the PP, which has lost points to the Socialists leading in polls, has toughened its discourse on the subject.

Leftist analysts see the party as wooing working-class voters living alongside immigrants in low-income neighbourhoods and even the far right.

Rajoy pledged to make immigrants sign a contract agreeing to respect Spanish laws and customs and to pay taxes.

The PP also wants Muslim girls to take off their headscarves at most schools, and would expel even longer-term immigrants if they commit crimes.

The proposals sparked a critical response from leftist parties and immigrant associations, which asked whether respecting Spanish customs meant that everyone should eat potato omelette and attend bullfights.

The PP was accused of racism and xenophobia.

Undaunted, Rajoy went on to warn that immigrants could hamper Spaniards' access to social services, and slammed Zapatero for having legalised more than half a million migrants in 2005.

The PP legalised even more while in power, Zapatero retorted during a live television debate watched by more than 10 million Spaniards.

The number of immigrants has soared from 1.8 percent of the population in 1990 to 11 percent. The largest groups include nearly 560,000 Moroccans, 530,000 Romanians, 420,000 Ecuadorians and 260,000 Colombians.

Media coverage has focused on the dangerous sea crossings made by tens of thousands of Africans to the Canary Islands.

The PP says there are 1.2 million undocumented immigrants in Spain, but the daily El Pais put the real figure at less than 200,000.

In 2000, Spain was shocked by violence against North Africans in the agricultural town of El Ejido, where about 80 people were injured in clashes between locals and migrants.

Nothing comparable has occurred since, but sociologists say there is a "low-level" racism which has the potential of growing.

"I take my son to an expensive private nursery, because the public ones are filled with children of immigrants," one Madrid mother said.

Immigrants' associations signed a manifesto against such views with the backing of professors from nearly 40 universities, accusing the PP of aggressiveness against foreign workers.

Sectors such as construction, agriculture or care of children and the elderly would collapse without the presence of immigrants, the Socialists point out.

Immigrants paying taxes and social security contribute to state coffers EUR 5 billion more than they cost the state, according to figures quoted by El Pais.

Immigrants have also helped to save Spain's birth rate, which has gone up from 1.16 live births per woman in 1996 to 1.37 in 2006.

In the past century, millions of Spaniards emigrated to seek better lives in Latin America or other European countries, but Spain's economic development has turned it from a country of emigration to one of immigration.

The one point that Zapatero and Rajoy agree on is that immigrants must come in legally.

Zapatero, whom polls give as the winner on Sunday, has sought to combine frontier controls and the expulsions of tens of thousands of illegals with moves to favour legal immigration.

Spanish companies annually hire about 200,000 people from countries such as Romania, Morocco or Colombia to work as fruit pickers, masons, waiters and the like.

As the government has increased cooperation with west and central African countries, hundreds of their citizens have been able to come in with work contracts as well.

[Copyright dpa 2008]