PEERS criticised plans for a Severn Barrage in a high-profile debate in the House of Lords.

Several used the second reading of the Marine Bill as an opportunity to attack plans for a barrage.

The Bill, which sets up a new Marine Management Organisation, is intended to improve marine conservation and streamline maritime planning issues.

Peers welcomed the Bill, but pointed out that the damage a Severn Barrage would bring to biodiversity and the maritime economy in the region runs contrary to the principles behind the legislation.

Labour's Lord Davies of Coity said: "All the environmental agencies and representative bodies believe that a barrage would be an unmitigated ecological disaster.

"Water quality, flooding and sewage are other very real concerns.

"The archaeological damage would be immense and the interruption to navigation on the Severn could be fatal to the ports of Bristol and Gloucester.

"The Government's advisers, DTZ, have said that the barrage would threaten thousands of jobs and create an economic deficit of around £500 million."

According to Stop the Barrage NOW, the debate highlighted concern the impact a barrage would have on biodiversity and fish stocks, ports and shipping, flooding and the estuary's archaeological heritage.

Campaigners are asking people concerned about the impact to sign a petition to stop any further money being spent.

Instead, they are calling for further research into alternative renewable solutions in the estuary, such as the possible development of tidal stream generators, which can be placed safely and unobtrusively in locations where they can provide all the benefits of renewable energy without the huge cost and intrusive nature of a fixed barrage.

Stop the Barrage NOW is a coalition of organisations and individuals campaigning to persuade the Government to focus on alternative tidal energy schemes in the estuary.

In the next few months, the campaign will be lobbying to persuade the Government and the Department for Business, Enterprise and Regulatory Reform that a barrage is not economically or environmentally viable.

Campaigners want any form of barrage to be excluded from a shortlist of proposals to generate renewable energy from the Severn.