Lib Dem MP Dan Rogerson has said he is "delighted" about a planned reduction of water bills in south west England.
Average annual South West Water bills are £517, which is £157 higher than the national average.
However Chancellor George Osborne used his Autumn Statement to announce that households in Devon and Cornwall will see their water bills cut from 2013.
Mr Rogerson - the MP for North Cornwall - said he wanted the change to have "maximum impact without unintended consequences".
Meanwhile his Conservative colleague for Newton Abbot, Anne-Marie Morris, said she didn't want any future changes to EU legislation to "erode the benefits".
The move, which will cost the government £35m a year, has been confirmed by the Consumer Council for Water and South West Water.
The announcement follows a review by senior civil servant Anna Walker into the affordability of water and sewerage charges.
South West Water (SWW) blames the cost of cleaning up bathing water for much of the extra cost.