Following Vane's move to Scilly, the Cavalier Parliament passed a resolution in November 1661 demanding his return to the Tower for trial. Charles temporized, and in January 1662 the Parliament renewed the demand. Vane was moved back to the Tower in April 1662, and on 2 June 1662 he was arraigned on charges of high treason against Charles II. The trial began on 6 June before the Court of King's Bench, with four judges headed by Lord Chief Justice Robert Foster presiding, and with the king's attorney general Sir Geoffrey Palmer prosecuting. As was typical of those accused of treason, Vane was denied legal representation. He defended himself against charges of making war against the king during the civil war by asserting the sovereign power of parliament. Accused of imagining the death of the king in 1659, he argued that it was not possible to commit treason against a king not in possession of the crown. When the prosecution argued that the king was always in "de jure" possession, Vane pointed out that this rendered invalid the charges that he conspired to keep Charles II from exercising his power. The judges stepped in to point out this was irrelevant. The jury, which was packed with royalists, convicted him after thirty minutes of debate.