Athanasius's first problem lay with Meletius of Lycopolis and his followers, who had failed to abide by the First Council of Nicaea. That council also anathematized Arius. Accused of mistreating Arians and Meletians, Athanasius answered those charges at a gathering of bishops in Tyre, the First Synod of Tyre, in 335. There, Eusebius of Nicomedia and other supporters of Arius deposed Athanasius. On 6 November, both sides of the dispute met with Emperor Constantine I in Constantinople. At that meeting, the Arians claimed Athanasius would try to cut off essential Egyptian grain supplies to Constantinople. He was found guilty, and sent into exile to Augusta Treverorum in Gaul (now Trier in Germany).
Is there an answer to this question (If it cannot be answered, say "unanswerable"): Who claimed Constantinople would cut off grain supplies?
unanswerable