Exclusive - Bulgarian nationalists may topple government over Russia sanctions

SOFIA (Reuters) - Bulgaria's nationalist Attack party will work to topple the government if Sofia backs a new round of Western sanctions against Russia over its annexation of Crimea, the party's leader told Reuters in an interview on Tuesday.

Attack holds the balance of power in the Bulgarian parliament, and its threat is an extreme example of the domestic pressures European governments face in taking a position on the worst crisis in East-West relations since the Cold War.