The grandson of Sir Richard Corbet, M.P. Shrewsbury 1678-81, Corbet was related to Richard, 2nd Earl of Bradford and his son Lord Henry Newport. A Whig like his father, who had founded a Shrewsbury club in 1684 to preserve Whig principles,
Returned on petition in 1723, he did not stand in 1727 but was re-elected after a close contest in 1734. He gave all his known votes for the Government, but was absent from the division on the Spanish convention in 1739. In the Cockpit list of 1742 he was classed as a follower of Henry Arthur Herbert, later Lord Powis. After the hard fought election of 1747 he decided not to seek re-election, writing to his brother that he had to support the interest entirely at his own cost: ‘scarce a letter comes but attended with some complaint or other as to my part’.
