Cracks are showing in Russia's leadership as a slowdown in the economy is beginning to cause rifts at the heart of the government, with one academic telling CNBC on Thursday that the economy poses the biggest threat to the country's leadership.

Prime Minister Dmitry Medvedev warned on Wednesday that while Russia's economy had not performed badly in 2012, falling commodity prices risked pushing the country into a recession, but the government will stick to its adopted fiscal rule, he told parliament on Wednesday.