Spain on Friday launched a legal challenge to defend plans to explore for oil and gas off the Canary Islands, a popular tourist destination.

Authorities in the Canaries oppose the government-backed plan by oil giant Repsol to prospect under the seabed near the Spanish Atlantic archipelago and have said they will let locals vote on the plan on November 23.

The conservative government in Madrid decided Friday to appeal to the Constitutional Court against that referendum, Deputy Prime Minister Soraya Saenz de Santamaria said.

"This appeal motion has already been signed" by Prime Minister Mariano Rajoy, she told a news conference after Friday's weekly cabinet meeting.

She said the government would challenge the vote on the same legal grounds it has used to get a planned referendum on independence for the Catalonia region suspended.

In both cases, the government says the regional governments are not authorised to hold referendum-style votes.

"We are talking about matters that are in the power of the state, not of the Canary Islands government," Saenz said.

Madrid outraged the Canaries' regional government, residents and environmental groups in August by giving Repsol the all-clear to explore near the islands' coasts.

The company has been authorised to spend three years probing below the sea bed about 50 kilometres (30 miles) from the islands of Lanzarote and Fuerteventura.

Residents of the archipelago off the northwest coast of Africa fear Repsol's explorations will harm the environment and disrupt the tourism industry on which their economy relies.

Under the terms of the licence, Repsol must provide a deposit of 20 million euros ($25 million) "to cover its environmental responsibilities".

Those safeguards have not convinced the islands' government or residents, however. Protesters demonstrated across the eight inhabited islands of the archipelago on October 18.

Greenpeace said its campaign boat Arctic Sunrise was heading to the island of Lanzarote on Friday evening and would also visit two other ports in the Canaries over the coming 10 days to support the protests.

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