The Thames is one of the country’s top-10 most improved rivers, according to the Environment Agency.

Despite the success, Richmond’s MEP Sarah Ludford has vowed to continue her campaign for a crackdown on pollution.

The Liberal Democrat MEP, along with London Assembly member Dee Doocey, has been calling for improvements for the past 10 years, and presented a petition to the European Parliament in 2005 protesting against sewage overflows.

She said: “Environmental improvements have been one of the success stories of the European Union (EU). Pollution pays no respect to national boundaries, and having common commitment and legal obligations to meet has helped stimulate action and secure public investment.

“The Thames was declared ‘biologically dead’ in the 1950’s, and now there are many different species of fresh water fish living and thriving in the river.”

The UK will be required to meet new EU water quality targets by 2015.