Verney entered the Short Parliament in 1640, sitting as Member of Parliament for Aylesbury. He was re-elected MP for Aylesbury for the Long Parliament in November 1640. He was present in the trial of Thomas Wentworth, 1st Earl of Strafford in January 1641, making notes, and was knighted in March. Verney opposed William Laud before the Civil War, and sided with the Parliamentarians at its outset; however, when he did not partake in the Solemn League and Covenant in 1643, he was forced to flee into exile; three years thereafter his assets were confiscated. He went first to the Netherlands, met his wife in Blois in France, where she died, and arrived then in Italy. He was disabled from sitting in Parliament on 22 September 1645.