The Government has been urged to slash wind power subsidies to fund the development of marine power off the Westcountry coast.
North Devon MP Nick Harvey has called on ministers to reform the funding regime to ensure "adequate investment finance" is available for offshore green technology.
If not, the Liberal Democrat MP went on, ministers should take subsidy away from "30-year-old wind technology" and pump cash into new renewable energy.
Mr Harvey, a former minister, pointed to successful test turbines generating power from the sea's currents off Lynmouth, North Devon, eight years ago that have yet to make it to commercial scale.
In August, ministers cut subsidies to onshore wind farm developers get by 10%, but many MPs want the Government to go further.
During Energy Questions in the House of Commons, Mr Harvey asked Energy Minister John Hayes what he could do to "ensure that adequate investment finance is available to marine energy and its attendant infrastructure?"
He went on: "Is he aware that it is now more than eight years since a marine current turbine was trialled off the north Devon coast, which more than twice exceeded expectations for energy production but has not come to market because of a lack of finance?
"If he cannot make new finance available, can he re-balance existing finance away from 30-year-old wind technology and towards the new technologies that could drive forward the process of de- carbonisation?"
Mr Hayes responded that the Government had sanctioned two "marine energy parks" – the first was in the South West – and the UK now boasts six of the eight major wave and tidal energy projects around the world.
He went on: "We are investing in that significantly, but I will look at it again because it is absolutely right that we are at the cutting edge of technological change when that can contribute to the energy mix."
Bristol-based Marine Current Turbines planted the world's first experimental marine current turbine at Foreland Point, near Lynmouth on Devon's North coast.
Conservative backbenchers were leading calls for onshore wind to have cuts of up to 25% to its subsidy, which is paid for from household energy bills.
Onshore wind, which has drawn criticism for being ineffective, over-subsidised and being a blot on the landscape, faces another subsidy review next year.
Tory Mr Hayes, appointed energy minister in this year's reshuffle, is a known sceptic of onshore wind but his boss – Energy Secretary Ed Davey, a Lib Dem – is a proponent.
More than 100 wind turbines are in operation across the Westcountry, and the UK's biggest onshore wind farm in North Devon will be up and running shortly. The massive Fullabrook wind farm between Barnstaple and Ilfracombe consists of 22 giant turbines. Many more are pending.
The nascent South West Marine Energy Park will mean the region is the sector's focal point in the UK. Cornwall's Wave Hub, a wave energy "nursery" in Falmouth Bay, and research facilities at Plymouth and Exeter universities, are all key to the "virtual" park plan which will gravitate around the ports of Falmouth, Hayle, Plymouth and Bristol.
Meanwhile, North Cornwall Lib Dem MP Dan Rogerson asked ministers to kick on with "hot rocks" geothermal power. The technology, which uses the heat of the Earth's core to generate power, is being pioneered in the Westcountry, with planning permission granted to two major projects in Cornwall, including a £35 million scheme at the Eden Project.
"This is an exciting opportunity for Cornwall." he said.