A TIDAL barrage across the Mersey could destroy wildlife and cause flooding at Halton, according to the RSPB.

Yet, there is a chance that one could be built on the estuary within the next 10 years, despite warnings from conservationists.

The group fears one could be built after a report from The Mersey Tidal Power project, led by developers Peel Energy and the Northwest Regional Development Agency, revealed it is considering a barrage in a shortlist of four options to generate tidal energy. If a tidal barrage is chosen, it could be operational by 2020.

Peter Robertson, the RSPB’s conservation manager for Northern England said: “The RSPB supports clean renewable energy schemes but only if they do not pose a significant threat to the environment.

“Old-fashioned methods of generating tidal power – in particular tidal barrages -– carry huge risks to sensitive environments such as the Mersey Estuary.”

The RSPB claims an official Dutch report, which outlines the effects of a storm surge barrier built across the Oosterschelde estuary in the 1980s, found the barrier led to the loss of mudflats, leading to higher waves and water levels and reducing feeding grounds for birds.

The Mersey Estuary is designated as a Special Protection Area (SPA).

The estuary supports an average of almost 86,000 waterbirds annually.