Spain's big gamble: could the king of Vegas casinos Sheldon Adelson help fight a jobs crisis?

It sounds almost too good to be true: at a time when one in four Spaniards are out of work, for the last few months US casino tycoon Sheldon Adelson has been weighing up whether to build a $21bn (£13.3bn) tourist-cum-gambling resort, which is being dubbed "EuroVegas", outside Madrid or Barcelona. And the city that is chosen for what it is claimed will be Europe's biggest-ever such resort may feel it has hit employment's jackpot: EuroVegas, it is claimed, will create up to 250,000 new jobs.

Madrid appears to be well ahead. Earlier this month Mr Adelson made an unannounced visit to a possible site outside the capital. Flying in by private jet from Israel, he and his wife Miriam Ochshorn made an hour-long on-site inspection of the possible site near the capital's dormitory town of Alcorcón.

By the time the Madrid government had officially confirmed the visit, Mr Adelson, having spent no more than four hours in Spain, was en route to his Las Vegas home. A definitive decision is expected before the end of May.

But as a group of some 150 protesters against the project gathered outside Alcorcón town hall the week before Mr Adelson's visit would suggest, not everyone is convinced of the benefits.

In an echo of Goya's famous 3 May 1808 painting of a French firing squad killing Spanish partisans in the Napoleonic wars, the high point of the demonstration in Alcorcón (also held on 3 May) was a mock "execution" of a figure representing the local environment – one of their key fears being that pressure on politicians to cut Spain's jobless totalis so high that potentially negative ecological consequences of projects like EuroVegas will be ignored.

"A project on this scale" – ranging from 12 hotel complexes, each with 3,000 rooms, to six casinos with 18,000 slot machines – "will have a huge ecological impact, and Madrid's environment is already in very poor shape," says Rodrigo Fernández of the Plataforma-EuroVegas-No (PEVN) movement.

"The only justification for this project is employment. People are desperate for work, and this project exploits their dramatic personal plight."

Mr Adelson says Spain's jobless total which "assures us the support of the government" is one reason for his company, Las Vegas Sands (LVS), opting for Spain.The other is the good weather.

"What is really disturbing is the lack of information. We only have leaks to the media on the negotiations between EuroVegas and the local government." says Mr. Fernández. "All we know for sure is that there would be a huge increase in infrastructure: more roads, more underground and overland railways, maybe a bigger airport, and the environmental damage that inevitably would occur when you are building hotels with 36,000 rooms."

Environmental studies show the slot machines would have as much electrical consumption as Majadahonda, a medium- sized Madrid dormitory town with a population of 65,000, he claims.

In Mallorca last month, some 7,000 demonstrators protested against the proposed building of a hotel resort by the beach of Es Trenc, one of the few stretches of coast unspoiled by urban development. The construction would, according to Spanish newspaper El País, be the biggest hotel constructed in the Balearics since Franco's death in 1975.

"It's going to be horrible," says teacher Beatriz Mohedaño Lemauft, who regularly uses the beaches on Mallorca's south side and who joined the protest, "ecologically, a real disaster for the area. Okay, so the hotel is not going to be on the beach itself, but it's right next to it and is going to have a huge impact."

The hotel's backers say their €120m (£97m) investment could create 300 jobs. But Natalia Martín, an activist with the Ecologistas en Accion movement who specialises in coastal laws, says quick-fix employment must not be the only consideration for such projects.

"Whenever there is an environmental law which clashes with economic development, we believe the government wants to weaken that law," Ms Martín argues. "Spain's current legislation on coastland has been in existence since 1988 and it allows companies to develop franchises on some stretches for 30-year maximums. But in the case of an oil refinery in the Basque Country they've just given them another 30-year-extension on what is actually public property."

As for EuroVegas, the environment is just one area where questions are being asked – and no answers given: all that is known is that Las Vegas Sands has "development needs", which it refuses to make public.

An emailed list of questions to the company from The Independent about the "development needs" brought no response. Spain's heavyweight press have reported alleged requests by LVS for an easing of Spanish labour laws, lifting of visa restrictions on foreign employees, two-year tax breaks and permission to loophole health laws on smoking in public places.

Ultimately, whatever Las Vegas Sands asks for, the lure of wiping out half of Madrid's unemployment total at a stroke when Spain is in its worst recession for decades may prove too hard to resist.

"Rejecting a project out of hand, when we know nothing of its details but which could contain the possibility of creating employment and reactivating the economy, seems a little rash," Paz Gonzalez, head of Madrid's housing department, told El Páis.

If Spanish politicians need to be reminded of the difficulty of reversing a controversial building decision after the bulldozers move in, they might recall the Hotel El Algarrobico in Almería, 500km further south.

A 21-storey, 411-room never-used hotel in the middle of Cabo de Gata Natural Park and 14 metres away from previously virgin coastline, the hotel has been pending demolition for over six years. But the builder, Azata Sol, said in 2009 the hotel's 65,000 cubic metres of cement "are encrusted in the earth" which makes demolition impossible.

Something on the scale of EuroVegas or Es Trenc in Mallorca, one imagines, would be even harder to backtrack on. But the pressure for such allegedly employment-rich projects is steadily mounting in today's jobless-hit Spain.