Spain takes pride in its universal health care but Europe's debt crisis has spurred tough budget cuts that will bring sometimes life-saving treatment for illegal immigrants to an abrupt end.

Carmen Maria, a 33-year-old woman from Nicaragua who arrived in the country in 2010, has no legal ID in Spain but has benefitted from free health coverage for her illness nonetheless.

She has been working as a cleaner and despite failing to obtain residency she was able to enjoy the same health care as any legal Spanish citizen.

Ten months ago she was diagnosed with dermatomyositis, a skin disease which can be associated with a tumour and lead to potentially fatal complications.

"It's considered a rare disease and my condition requires constant medical monitoring," said Carmen Maria, whose husband and four children still live in Nicaragua.

Prime Minister Mariano Rajoy's government, faced with soaring unemployment, rising debt and a slide into recession, has launched an austerity plan aimed at cutting the deficit from 8.5 percent of GDP last year to 5.3 percent in 2012.

To achieve the package's target of cutting health expenditure by seven billion euros ($9.3 billion), only legal immigrants will retain health coverage as of September 1.

Among illegal immigrants, only children, pregnant women and emergency cases will qualify for free treatment.

"This will only put Spain on a par with other European Union countries," according to Health Minister Ana Mato.

The measure will leave half a million illegal immigrants who have been counting on Spain's health coverage with no safety net, and several organisations have been sounding alarm bells.

Carmen Maria decided to seek help from the group SOS Racismo, saying, "I'm alone here, I don't have anyone."

"The economic crisis, no matter how severe it is, should not be an excuse for stripping immigrants of all their rights," SOS Racismo said, describing access to health care as "a fundamental right".

"This is a very dangerous situation," said Vladimir Paspuel, who heads Ruminahui, a Spanish-Ecuadorian association that offers social and legal assistance to immigrants.

"It can have life-threatening consequences in cases where a disease is not treated in time," he said.

"Another thing is that it sends a subliminal message to Spanish society: 'Illegal immigrants are the ones who are pilfering the money, they are responsible for the crisis'," he explained.

In a bid to defuse any surge in anti-immigrant rhetoric among the public following the conservative government's decision, groups such Ruminahui point out that immigrants are more sparing with their visits to the doctor.

According to a study carried out by a health expert and published in the El Pais daily, immigrants on average go 5.05 times when Spaniards go 7.65 times over the same period.

"I don't go to the doctor more than twice a year," said Wilson Quintero, a 42-year-old Ecuadorian.

But scrapping health coverage for 500,000 Latin Americans, North Africans and Eastern Europeans in Spain "is a serious problem", he said.

"If someone falls ill and doesn't have a steady job, what is he supposed to do? It will become very difficult," he said.

Wilson has lived in Spain since 2002 and worked as a builder until the real estate bubble burst, which led him to lose first his job and then his residency.

Spain's unemployment rate is the highest in the industrialised world at 24.4 percent. It is even higher among immigrants at more than 40 percent.