Under the plans, which environment minister Steve Reed was due to announce at the UN Ocean Conference in France later Monday, bottom trawling will be banned in another 30,000 square kilometres (11,600 square miles) of English seas in Marine Protected Areas (MPAs).

There are currently 181 MPAs covering 93,000 km2, or 40 percent of English waters.

Around 18,000 km2 of those waters are currently protected from harmful fishing activity, but that would rise to 48,000 km2 under the government's plans.

Bottom trawling, in which heavy nets dragged by chains are pulled along the seabed, "is damaging our precious marine wildlife and habitats", Reed said in a government press release.

"Without urgent action, our oceans will be irreversibly destroyed -- depriving us, and generations to come, of the sea life... which we all enjoy.

"The government is taking decisive action to ban destructive bottom trawling where appropriate," he added.

- UN oceans summit -

World leaders started gathering on the French Riviera on Sunday ahead of the high-level summit to tackle a deepening crisis in the oceans driven by overfishing, climate change and pollution.

The United Nations says oceans face an "emergency" and the leaders gathering in Nice will be under pressure to commit money and stronger protections for the seas and the people that depend on them.

The UK says its bottom trawling plans would help protect rare marine animals and the delicate seabeds on which they rely.

The British consultation will invite marine and fisheries stakeholders to share their views and will run from Monday until September 1.

The measures would affect marine habitats ranging from subtidal sandbanks to gravels to muds, and support species such as lobster, clams, soft corals and langoustines.

"For too long damaging activities have been allowed to continue within many of our MPAs which are supposed to protect the seabed," said Joan Edwards from the Wildlife Trusts, a federation of charities.

They "have been campaigning for a long time for better management of our MPAs and therefore welcome the news today of a consultation to ban bottom-towed trawling in over 40 offshore sites," she added.

Elsewhere at the UN conference, the UK was set to pledge a further pound4 million ($5.4 million) to the Global Fund for Coral Reefs, bringing the country's total contribution to the fund up to pound40 million.