The mayor of a Spanish town who helped raid supermarkets to give groceries to the poor will step up his campaign against the country's austerity measures.

Juan Manuel Sanchez Gordillo, a regional lawmaker and mayor of Marinaleda, population 2,645, will begin a three-week march to draw attention to families hit hard by Spain's economic crisis, Reuters reported Wednesday.

Juan Manuel Sanchez Gordillo has raised the ire of the national government for his anti-austerity campaign. (Cristina Quicler/Agence France-Press)

Seven people have been arrested for their roles in two grocery raids, in which labour unionists loaded up supermarket carts and walked out without paying.

Sanchez Gordillo stood outside the stores during the raids, Reuters said, but wasn't arrested himself, because he has political immunity as an elected member of Andalusia's regional parliament.

"There are people who don't have enough to eat," Sanchez Gordillo told Reuters. "In the 21st century, this is an absolute disgrace."

Poverty levels are said to have risen more than 15 per cent since 2007, with a quarter of workers jobless and tens of thousands have been evicted from their homes.

Media coverage of the supermarket stunt has made the mayor a national celebrity.

His home region of Andalusia is one of the parts of Spain worst hit by the economic crisis: one worker in three is jobless, the news agency said.

His march will start in Jodar, which has Andalusia's highest unemployment rate.

The EU has demanded Spain shrink one of Europe's highest budget deficits to prevent the continent's debt crisis from spreading.

Sanchez Gordillo has long been a fringe figure on the national stage, known for criticism of the mainstream political parties, Reuters said.

"They say I'm dangerous," the news agency quoted him as saying. "And the bankers who are let off for fraud? That's not dangerous? The banks which borrow from the ECB for one per cent then resell that debt to Spaniards for six per cent — they're not dangerous?" he said.