Russia is making an audacious grab for the vast energy riches of the Arctic with an underwater mission to plant its flag beneath the North Pole.

A team of explorers plans to descend 4,300 metres (14,000ft) to the seabed in a miniature submarine tomorrow to stake Russia’s claim to an area of ocean the size of Western Europe. The polar expedition aims to prove that the Lomonosov Ridge, an underwater shelf that runs through the Arctic, is an extension of Russian territory.

The Kremlin has poured £40 million into the voyage, which is receiving blanket coverage on state television, to try to secure billions of tonnes of untapped oil and gas reserves under the ocean. Two members of the Duma, the Russian parliament, will plant the one-metre flag, made of titanium, during what will be the first manned journey to the seabed of the North Pole.

“This will be a truly historic dive,” Anatoli Sagalevich, chief of the Oceanology Institute at the Russian Academy of Sciences, told Itar-Tass. “The human eye has never seen the North Pole from a depth of 4,300 metres.”

Before the expedition left the northern port of Murmansk, Artur Chilingarov, 68, the expedition leader, said: “The Arctic is ours and we should demonstrate our presence.”

Mr Chilingarov is a deputy speaker in the Duma and president of the Association of Polar Explorers of the Russian Federation. His fellow submariner, Vladimir Gruzdev, said that the expedition would “remind the whole world that Russia is a great polar and scientific power”.

More than 100 scientists are on board the Akademik Fyodorov, Russia’s flagship research vessel, for what is the largest expedition yet organised to the Pole. A nuclear-powered ice-breaker, the Rossiya, is accompanying the ship.

Two deep-water submersibles will make three dives to the sea bed to try to confirm research by a Russian expedition in May suggesting that the Lomonosov Ridge is an extension of the Siberian continental shelf.

No country has jurisdiction over the Arctic, which is governed by the International Seabed Authority, but Russia has long sought to extend its territorial boundary. It lodged a demand for 1.2 million sq km (463,000 sq miles) of ocean in 2001 with the UN Convention on the Law of the Sea, which asked for more scientific data to support Russia’s case.

The expeditions are collecting data to back a fresh submission in 2009, the centenary of the first journey to the North Pole. At stake are vast reserves of oil and gas that are considered increasingly viable economically as climate change makes the Arctic less hostile to exploitation. Russian geologists argue that the area contains 10 billion tonnes of oil and gas, though some estimates put the total closer to 100 billion tonnes.

Russia’s claim to the North Pole is opposed by the four other Arctic countries — Canada, the United States, Norway and Denmark, through its sovereignty over Greenland. Under international law, each nation is entitled to control an economic zone within 200 miles of its continental shelf, but the limits of the shelf are disputed.

Denmark and Canada argue that the Lomonosov Ridge is connected to their territories and dispatched a joint expedition last year to bolster their claims. Stephen Harper, the Canadian Prime Minister, ordered a new fleet of patrol vessels last month, saying that they were needed to defend “our sovereignty over the Arctic”.

Russia’s determination to claim the territory poses particular problems for the US, which has refused to ratify the Law of the Sea Treaty governing disputes over exploitation rights, restricting its influence on the Arctic’s future.

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