Smirnov was expelled from the Communist Party at the 15th Party Congress in December 1927 along with the rest of the United Opposition. On 31 December 1927, he was told that he had been sentenced tp three years exile in the Ural region for 3 years, and was given less than a week to leave Moscow. By chance he had just had his teeth removed, in the expectation of getting false teeth, so when to the Urals missing half his teeth. On 29 January 1930, he was arrested for being five minutes late in reporting to the local Ogpu for a routine check, and sentenced to three years in prison, and held in an 'isolator' at Verkhne-Uralsk.