Greenpeace activists board Kremlin state-owned oil platform in Arctic in protest at rate of ice melting

Greenpeace has signalled its determination to try to halt the Kremlin's march into the Arctic with activists led by its executive director boarding an oil platform belonging to state-owned Gazprom.

It is the first time that the green group has taken "direct action" against the Russian drilling and comes amid alarming new evidence about the speed with which Arctic sea ice is melting.

Six environmentalists in inflatable boats launched from Greenpeace's Arctic Sunrise ship approached the Prirazlomnaya rig 600 miles east of Murmansk and used mooring lines to climb the rig and attach a "portaledge" to the side of it.

Kumi Naidoo, the executive director of the green group, unfurled a banner in Russian reading "Save the Arctic!" before the crew of the Russian platform attacked them with water hoses.

"Like Shell's reckless plans to drill in Alaska, it's not a question of if an oil spill will happen, but when. The only way to prevent a catastrophic oil spill happening in this unique environment is to permanently ban all drilling now," said Naidoo.

Gazprom Neft Shelf, the Gazprom subsidiary that holds the licence for the field, said the Greenpeace activists were invited to come on board for a "constructive dialogue" but they declined. The campaigners later called off the protest.

Russia has long had ambitions to produce lots of oil and gas from the Arctic and has recently signed Arctic agreements with western firms such as ExxonMobil to kickstart the campaign. The Prirazlomnaya – a steel structure, part of which was used previously to produce oil on the Hutton field in the UK North Sea – is an all-Russian pioneering venture that hopes to start producing hydrocarbons from next summer.

Some of the estimated 526million barrels of oil in the field would be loaded on to tankers in the Arctic and carried back to Murmansk or perhaps direct to petroleum centres such as Rotterdam.

Greenpeace, which has confronted other Arctic drillers such as Cairn Energy off Greenland and is trying to stop Shell working off Alaska, has put the far north at the centre of its current campaigning.

It recently claimed that Gazprom's oil spill response plan for the platform had expired and says any drilling without a new plan in place would be illegal.

But the Kremlin has recently announced plans to crack down on "foreign" non-governmental organisations and the court sentences against Pussy Riot female punk and protest band indicate Russia is in no mood for internal or outside criticism.

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