Householders in Sussex must start treating water as a scarce resource, the Government has warned.

In an interview with The Argus, David Miliband, the Secretary of State for the Environment, Food and Rural Affairs, said water shortages in the county and other parts of the South-East demonstrated how climate change was a local as well as an international issue.

Mr Miliband said: "The days when we could consider water as an infinite resource are gone. Water is a scarce resource even in a wet country."

Mr Miliband said the Government was looking into plans to introduce widespread water metering, which experts claim could reduce use by ten per cent.

Currently, only 30 per cent of homes use meters.

He said: "In those areas which are water-stressed, you should have a tougher approach. We are looking at proposals for extensions of water metering in the context of making sure vulnerable people don't get hit."

But the cabinet minister ruled out creating a national network of interconnected reservoirs and waterways to transfer water from the wetter north to drier areas in the South.

He said: "All the economic and environmental evidence says a national water grid is not a good idea. The environmental cost of burrowing through from Tyneside down to Oxford with a water tunnel would be fantastically expensive and fantastically environmentally damaging."

But Greg Barker, Conservative MP for Bexhill and Battle, said the Government was at fault for failing to provide the strategic vision needed to help the water industry cope with shortages.

Mr Barker, a shadow environment minister, said: "The industry is totally rudderless with no clear view of who needs to do what. The Government is failing the consumer by constantly passing the buck.

"You can't build more houses in the South-East unless you have got the infrastructure to support them. Any serious analysis of the water problem comes back to the Government's unsustainable house building programme, which is going to make things much worse."

Mr Miliband said farmers were on the "front line" in the fight against global warming and he was sorry for delays that had dogged the Rural Payments Agency, forcing farmers to wait for subsidies.

And he admitted that sorting out the problems before next year's payments were due would be "challenging".

He said: "Farmers have the right to expect high standards from the agency. Have we delivered on that? No. Has this caused hardship and difficulty? Yes.

"It is essential we put it right quickly."