 In April 1640, Luke was elected Member of Parliament for Bedford in the Short Parliament and was re-elected for the Long Parliament in November 1640.In the latter election he is known to have had the support of much of John Bunyan's future congregation.Luke was governor of the Parliamentary outpost in Newport Pagnell, Buckinghamshire from late 1642 until June 1644 during the English Civil War During the war he was also Scoutmaster to the Earl of Essex.