Spain has been severely criticised by French officials for its handling of the Prestige oil tanker disaster.
Spain is proud of its clean-up operation (Image: WWF-Canon/Raul Garcia)
On the first anniversary of the vessel's break-up, an official French panel said Madrid's actions had exacerbated the tragedy.
Spain had prevented emergency workers from boarding the vessel until it had been towed out to sea.
The French President, Jacques Chirac, has called on Europe to do more to protect its coastlines and seas.
The report was commissioned by the French MP Philippe de Villiers, a senior politician from Vendee, where coastlines were covered by oil seeping from the Prestige.
According to the study, "good sense" should have told Spain to bring the stricken vessel into the port of La Coruna.
The single-hulled tanker, registered in Liberia, had reported difficulties on 13 November last year and after drifting for six days, had sunk on 19 November spilling 50,000 tonnes of oil into the sea.
Mr De Villiers said he would take legal action against Spain for the part it played in the disaster, which he says is revealed by the report.
According to the Royal Society of the Protection of Birds in Scotland, nearly 4,000 Scottish puffins were washed up dead as a result of the spill.
Another 300,000 British seabirds - mainly Scottish guillemots and razorbills - were killed, says the RSPB.
"This incident was avoidable. Governments at home and abroad must take urgent measures to protect the most sensitive parts of Europe's coast and seas," the society's Darren Kindleysides said.
In Spain, fishermen have been living off hand-outs for months.
The Spanish Government has been trumpeting the success of its clean-up operation; however environmental groups have planned demonstrations to coincide with the Prestige anniversary.
The World Wild Life Fund says up to 10,000 tonnes of oil still remain in Spanish and French waters.
A study published by a Spanish University warns that high levels of toxic chemicals have been found in sea food, reports BBC correspondent in Madrid Katya Adler.
President Chirac has urged "Europe to do more to make its voice heard", according to his spokesman Jean-Francois Cope.
Last month, the EU agreed on prohibiting single-hulled tankers carrying heavy fuel oil from its ports.
The United States adopted similar legislation a decade ago after the 1989 Exxon Valdez disaster in Alaska.