He was Mayor of Lostwithiel in 1802 and 1808, and in 1811 inherited the vast Menabilly estate from his uncle Philip. This gave him control of the Rashleigh family's pocket borough of Fowey, and at the 1812 general election he returned himself as Member of Parliament (MP) for Fowey. He sold the control of the borough in 1817, and at the 1818 general election retired from the House of Commons.[2]
He died in 1855 at Kilmarth, near Menabilly. He had married twice: firstly Rachel, the daughter of William Stackhouse of Trehane, with whom he had two daughters; and secondly Caroline, the daughter of Henry Hinxman of Ivychurch, Wiltshire with whom he had two sons and four daughters. Menabilly descended to his son William Rashleigh.