The Wind in the Willow's character Ratty was given cause to celebrate after he and other water voles were given full legal protection today.

Speaking at the London Wetland Centre in Barnes this morning the Minister for Biodiversity, Joan Ruddock, announced that the animals - Britain's most endangered mammal - would be protected against being killed, injured or taken from the wild.

Police will now have the power to prosecute anyone who has deliberately persecuted the beasts.

The London Wetland Centre, run by The Wildfowl and Wetlands Trust (WWT), has a thriving water vole population at all six of its centres after they were introduced in 2001.

The WWT's director of conservation, Debbie Pain, said: "Water voles have suffered the most dramatic decline of any British mammal. Over the last century numbers have plummeted to a tiny fraction and they are completely gone from many areas where they were once common.

"So we're delighted with today's news that they will get proper protection. It makes the law much clearer for people who manage land and it gives the police the power to deal with people who deliberately kill water voles."

The water vole, immortalised in Kenneth Grahame's novel The Wind in the Willows as the relaxed and river-savvy Ratty, has been in decline thanks to a loss of their habitat and the spread of American mink - their main predator.