A green tax on travellers to the Balearic islands should ensure their future as a major tourism destination by sustaining a fragile region, according to charity group Tourism Concern. Though major tour operators say the tax will deter tourists from going to the islands, Tourism Concern warns that without it, there might not be much left worth visiting.

The levy passed by the Balearics parliament last week adds about a euro (62p) a day to the price of a holiday, excluding children under 16 and pensioners.

Association of British Travel Agents spokesman Keith Betton said that could be enough to deter tourists in a highly price-sensitive market. But Tourism Concern director Tricia Barnett said: 'It is less than £5 a week per person. People have gone there as cheaply as they possibly can for a number of years. It doesn't seem to be such a terrible thing to contribute to the environmental regeneration of a highly degraded area.'

Spanish tourism officials have been trying to shrug off the Balearics' 'build high, get them in cheap' image by upgrading hotels and facilities. The tax is designed to carry on that work, generating about £40 million a year to help solve the problems of mass construction without the proper infrastructure, said Barnett.

The money could be used to prevent sand erosion in some overdeveloped coastal areas, which was leaving them without beaches, she added. More changes needed to be made in Ibiza, where hotels still draw their water from local wells. 'There is a huge demand on scarce resources,' said Barnett. 'This is the result of wanting things cheap and thinking short term.'

Both Abta and large tour operators have condemned the tax for being selective and only being charged on hotel clients rather than tourists going to private villas. Hoteliers plan to appeal against the measure, which is unlikely to be imposed before next year. It has not been decided how the tax will be levied. A spokesman from package operator JMC added: 'We are not convinced there is a desire to improve the Balearic environment.'

But Adam Walsh, director of specialist operator Alternative Mallorca, welcomed the initiative. 'It is an eco-tax which, if applied correctly, can't be a bad thing,' he said.

Millions of UK tourists visit the Balearic islands every year with the majority heading for Majorca.