Abebe Hailu grew up in Ethiopia opposite a Swedish mission, so when he was forced to leave the country in the late 1970s he knew where he wanted to go.

"I already knew in Sweden the gap between the rich and the poor was not so big - everyone had a home and something to eat," he says.

Mr Hailu trekked for 50 days from Ethiopia to Somalia before finding his promised land and now spends half his time working as a train driver and the other half as a local councillor for the Social Democratic party in Rinkeby, a suburb of Stockholm that has a high immigrant population. "You can hear 70 languages here," he says.

When the Swedes go to the polls on Sunday, history indicates that more than two-thirds of the population of Rinkeby will vote for the Social Democrats, the party that has ruled Sweden for the past 12 years and for 65 of the past 74 years.

During their decades in power, the Social Democrats have erected a welfare state from which the people of Rinkeby have benefited greatly, receiving housing, education, job training and unemployment benefits, among other things. "This is our stronghold," says Mr Hailu.

But a growing number of Swedes do not see Rinkeby as Mr Hailu does - the shining example of a successful welfare state.

Jimmie Åkesson is the 27-year-old leader of the Sweden Democrats, a rightwing nationalist party.

"We want fewer immigrants," he says. "There have been too many in too short a time." Mr Åkesson advocates Swedish language, and history and culture tests for aspiring immigrants. "We want them to assimilate."

His manifesto is finding a growing audience. Four years ago the Sweden Democrats had seats in five local councils. Today they have 30. National support was 2.7 per cent in a recent poll, three times higher than four years ago.

In a recent mock election held by a Swedish news-paper, 11.9 per cent of people under the age of 24 voted for them.

The main reason, according to the European Union, was a youth unemployment rate of 23 per cent. Some people apparently feel the immigrant community is making it harder for them to get jobs.

Mr Åkesson sees other reasons for his surging popularity. First, there is growing frustration over high tax payments being used to provide benefits for the immigrant population. Second, none of the other parties even talks about the immigration issue.

"People don't like the current immigration policies but it is taboo to discuss it in Sweden today.

The big political parties don't want it discussed but I can tell you, this is what people are talking about when they are doing their jobs or eating breakfast. Under the surface, it is growing."

Sweden's demographics mean his support is likely to grow. The population is ageing, meaning more people are going to require expensive health and medical benefits at a time when the number of taxpayers is declining.

Sweden is struggling to maintain welfare payments at a time when the economy is booming.

In these circumstances, and over the course of the next generation, independent economists agree that either taxes will have to go up or welfare benefits come down. Both would exacerbate existing concerns over immigration.

Mr Åkesson believes a growing number of Swedes want their taxes spent on areas such as helping the elderly rather than on unemployment benefits for immigrants.

"This is also being felt in France, Denmark, Norway, the UK," he says.

The Sweden Democrats have shone a spotlight on an uncomfortable aspect of Swedish society - the looming structural weakness for the Nordic region's most successful welfare state.

But Mr Hailu says they are ignoring the fact that an ageing population needs tax-paying immigrants to cover its welfare bill.

"Immigrants do jobs that other Swedes don't want to do," he says. "If immigrants stop working, Sweden stops working."

But Mr Hailu represents a reason the Social Democrats have been repeatedly voted back into office.

He can remember drinking water from the same fetid drinking holes as camels during his long walk out of Ethiopia.

"The Social Democrats mean everyone has somewhere to live, everyone has something to eat. You can come here, get an education, get a job and build a family."

Additional reporting by Nadia Jaber