According to the 28-year-old mayor of the small village of Marinaleda, 60 miles from Seville in Spain's depressed southern region of Andalusia, "We're on a hunger strike to see if we can put an end to hunger."

As leader of a fast that has involved almost a third of Marinaleda's 2,500 population over the past five days, Mayor Juan Manuel Sanchez has himself shed nearly 14 pounds since last Thursday. The villagers are trying to draw attention to the plight of unemployed landless laborers in the area.

As many as 800 Marinaleda villagers joined the hunger strike, among them retired people and young children. Originally envisaged as a 48-hour gesture to end at the weekend, the strike was prolonged today by a hardline group amid reported solidarity fasts carried out by radical Christian groups in five neighboring villages.

A militant trade union group that organizes local peasant laborers today was finalizing plans for strike action and demonstrations to support Marinaleda, indicating a growing militancy reminiscent of the anarchist tradition that existed in the Andalusia region before the outbreak of the 1936-39 Spanish Civil War.

At the root of Marinaleda's protest is the demand for increased government funding for the more than 300 jobless men of the village who, as seasonal rural laborers, are not covered by state unemployment benefits. In theory, they are eligible for government support through a system known as "communal employment." The government directly funds the town or village council, which in turn employs the jobless in civic duties.

In practice, and certainly in the case of Marinaleda, the funds have often not been forthcoming. "Between January and August last year we received 14 million pesetas [$205,000] for communal employment. This year we have received eight million," [$117,000], said the mayor.

According to a spokesman for a radical local trade union movement, the Land Workers Syndicate, the case of Marinaleda and its lack of funding is not an isolated one. In national political terms, the endemic and growing underemployment in Andalusia, coupled with the radical peasant league-type organizing it has provoked, constitute a potential threat to Spain's experiment with representative government.

At a political rally held in Madrid last week, Congressman Rafael Escuredo, the socialist president of the regional parliamentary council, known at the Junta of Andalusia, accused the Madrid administration of ignoring the realities and problems of the south. "You cannot play with fire because if you do you get burnt," he said.

Escuredo was referring to a spate of fires in large estates in the south that have been reported intermittently since the spring. In certain cases the fires were claimed by a little-known organization calling itself the Armed Groups of February 28, who said the arson was aimed at Underexploited land. The date in the group's title refers to a referendum held in February in which Andalusian voters narrowly failed to endorse legislation for the establishment of an autonomous government in the area.

Escuredo warned of "grave times" for Andalusia and for Spain if the government fails to produce a new economic and political policy for the southern provinces.

Rural radicalism, chiefly anarchist inspired, has strong historical roots in Andalusia where recent studies show that despite moves toward agrarian reform, 2.5 percent of the land-based population in the region owns 64-percent of the land. Andalusia, stretching from Portugal right across the south to the Mediterranean is the largest single region in Spain.

Out of a population of nearly 6 1/2 million, nearly half a million are classed as landless laborers or jornalleros. According to trade union sources, there are an estimated 130,000 unemployed jornaleros who are the theoretical recipients of the "communal employment" funds. Even the employed journaleros will be actually working only for two to six months of the year on the seasonal crops.

Unemployment in Andalusia is officially held to be 20 percent, almost double the national figure. In terms of income, 1978 figures showed the per-capita income of the richest province in the region, Seville, to be $2,500 while the poorest, Jaen -- also the poorest province in Spain -- had an income of $1,800.

The depression that lies behind the tourist facade of the otherwise colorful Andalusia region -- the home of bullfighting, flamenco and sherry -- has been a constant feature in the region.

The organized militancy, however, is a relatively new phenomenon and appears to have picked up the radical roots repressed under the Francisco Franco dictatorship. It is spearheaded by the Land Workers Syndicate, which claims a membership of some 40,000 jornaleros chiefly in the provinces of Seville, Cadiz and Cordoba. A syndicate spokesman said the organization, many of whose leaders are affiliated with an extreme left-wing Maoist party, held an emergency meeting in Seville over the weekend. The meeting ended with a call to union groups in villages in the area to mobilize in support of Marinaleda.

Mayor Sanchez said he expected the hunger strike to end tonight. He vowed, however, that it would be repeated if the funds did not arrive. "We don't want to become the red Indian reserve of the 20th century," he said.