From New Scientist:
As sanctions deepen, just how crucial is Russian gas?
17:00 24 July 2014 by Jon Excell
Europe gets around 30 per cent of its gas from Russia, but some countries are more dependent on it than others: the Czech Republic and Finland, for example, import at least 80 per cent of their gas from the country, while Germany, which has been treading particularly carefully in its dealings with Putin, imports around 36 per cent of its natural gas and 39 per cent of its oil from Russian suppliers.
The situation in the UK is less clear. Gas imports account for around 70 per cent of supply, but because of the complex European network of pipelines and interconnectors that we rely on, it’s difficult to say exactly how much of that imported gas is Russian. Some reports claim that Russia supplies around 15 per cent of that total and others put this figure much lower. Russian energy giant Gazprom estimates that it sends 11 to 12 billion cubic metres to the UK each year, out of an overall UK consumption of around 84 billion cubic metres.