The biggest reform of planning for 20 years could result in the fast-track construction of major projects such as airports, incinerators, motorways and power stations.

It would also give homeowners the right to build conservatories, small extensions or loft conversions without planning permission.

Environmentalists and opposition politicians in Hampshire are worried that it could mean a restriction on public consultation over controversial projects such as the future expansion of Southampton Airport, making it easier for it to go ahead.

They say the 120-day public inquiry which after four years blocked £600m plans for a six-berth container port at Dibden Day could have reached a different conclusion.

The government this week announced its long-awaited planning White Paper which recommends a complete overhaul of planning to speed it up, make it more predictable and less bureaucratic, merging eight separate systems, Officials claim it could save £1 billion within a decade.

Major decisions would be handed to an independent 25-strong commission of experts who would veto or approve schemes, guided by "national policy statements" setting out the country's key infrastructure needs for the future.

The White Paper aims to prevent the seven-year wrangle over permission for Heathrow's Terminal Five by setting a limit of nine months for most decisions.

Communities Secretary Ruth Kelly said: "Nobody will agree with every planning decision but our reforms will make the system better focused, fairer, faster and more accessible for all".

The Conservatives say the system will "dump developments on local communities".

New Forest East Tory MP Julian Lewis, who helped defeat controversial plans to build the huge container terminal at Dibden Bay, has condemned the proposals.

Dr Lewis claims the terminal would have been approved if the new system being championed by ministers had already been in place.

Associated British Ports' (ABP) application to build the massive dock development between Hythe and Marchwood was rejected in 2004 after a long campaign by environmentalists.

ABP said it was vital to the future of Southampton docks.

However, in a House of Commons clash with Mrs Kelly, Dr Lewis said: "It took a five-year campaign and a year-long public inquiry to stop Associated British Ports.

"I believe if that process had been foreshortened there would now be a huge container port on the edge of the New Forest."

Mrs Kelly disagreed saying the Dibden Bay scheme was turned down partly because of its potential impact on bio-diversity.

She said: "That could have been identified at the beginning of the process, during the drawing up of a national policy statement."

"In fact it's precisely the sort of issue that ought to be identified in a national policy statement.

"If it had been identified, there would have been appropriate public consultation and the developers would have known the government's policy.

"The proposal would either have been accepted or would never have got off the ground."

Environmental campaigners fear the planning proposals will make it easier for the government to push through new roads and airport expansion schemes, which will lead to higher carbon emissions.

Chris Bluemel, from Against Airport Expansion at Eastleigh (AXE), said the government was "bulldozing over local democracy".

"The proposals will lead to more roads and airports when we should be doing all we can to tackle climate change.

"The government has shown little interest in local opinion or in tackling climate change.

"The planning White Paper will only serve Labour's friends in the roads lobby, and the aviation industry.

"It is hard enough for local communities to stand up against road schemes, without the government making it even harder."

Mary Finch, chairman of Airport Pressure Group, which opposes the expansion of Southampton Airport, said the White Paper was "not good for local people".

"You have to have time to look at plans and go through all the details and campaign against them. You need time to let local people know what's going on," she said.

BAA, which runs Southampton Airport and hopes to increase passenger numbers from 2m to 6m by 2030 with a possible second terminal, welcomed the White Paper.

A spokesman said: "This is a step closer to creating a clearer, accountable and more streamlined planning process which we hope will lead to greater clarity for infrastructure projects."

Jimmy Chestnutt, director-general of the Southampton and Fareham Chamber of Commerce called the proposals "long overdue".

"Anything that cuts down the length of time and cost that it takes to promote nationally important schemes is essential if this country is to remain competitive and meet the environmental and economic challenges of this century," he said.

Mr Chesnutt, while employed by ABP, was at the forefront of plans for a new container port at Dibden Bay.

He said he was concerned a "planning gain" supplement could lead to protracted valuation negotiations that would add to costs and reduce development land supply.

Richard Lambert, the director-general of the CBI, said the wider business community would welcome the signal the White Paper sends out.

"It introduces necessary reforms to help deliver the major projects, particularly in transport and energy, which the UK is crying out for if it is to remain competitive," he said.

ABP declined to comment on the government plans.