Nuclear power is winning new friends in Europe after Russia's fight with Ukraine over gas prices hit fuel supplies to the EU and triggered an energy policy re-think. Twenty years after the world's worst nuclear disaster at Chernobyl, the controversial energy source is back on the agenda and gaining support after the Russia crisis at the turn of the year alerted governments to the need for diverse and stable energy supplies, analysts said. ''This was a wake up call for a number of European governments and some of them think that nuclear power is the answer,'' said Dieter Helm, Fellow in Economics at the University of Oxford. Europe takes a quarter of its gas from Russia and its dependence on energy imports is rising as North Sea oil and gas production tails off. The nuclear lobby's unexpected boost from Russia come as its credentials as a power producer that doesn't pump out greenhouse gases has already forced it back into the reckoning in Europe, despite huge opposition from the green lobby and elsewhere. Britain, under pressure to fill a looming energy gap as its North Sea gas supplies dwindle, is widely tipped to put nuclear back at the heart of its energy policy in a strategy review due to be unveiled later this year. Nuclear supplies about 20 percent of the UK's power. Most of the country's ageing reactors are due to start closing from 2010, leaving just one operating in 2023. Russia's readiness to hit gas flows to Europe in a politically driven fight with Ukraine can only strengthen nuclear's hand as the UK and other governments shape long-term energy policy, analysts say. Russian gas giant Gazprom's Chief Executive Alexei Miller was in Berlin on Friday, vowing it would ensure safe supply of gas to Germany and the European Union in future. Analysts said worries, however, persist about Europe relying on Russian energy supplies. ''We used to say nuclear was ruled out -- the events of December mean the nuclear option Europe is ruled in,'' said Kelvin Beer, director of European gas and energy security at Ernst & Young in London. ''The Ukraine events have strengthened the case, Europe needs to put the nuclear option back in the equation,'' he said. Britain's ambitions to cut sharply its output of greenhouse gas emissions is also driving calls for nuclear, particularly as the government's bid to trigger a massive expansion of wind power has stalled amid problems gaining planning permission. In Germany, which gets about a third of its gas from Russia, the recent crisis has fired up the nuclear debate. Conservatives in the coalition government have urged a rethink of the country's plan to shut its 19 nuclear plants by 2020. Elsewhere in Europe, the Netherlands has decided to extend the life of its only remaining nuclear plant to 2033, from 2013, in a move to curb the country's dependence on imported oil. France, which launched an ambitious nuclear programme in the wake of the 1970s oil shocks and is the world's number two nuclear power producer, reaffirmed its commitment to the energy source last week with the launch of a fourth generation prototype reactor to be in use by 2020. PIN/REUTERS