In 1774 Owen was nominated for Montgomeryshire by the Powis family, and, supported also by many of the smaller landowners, was returned after a contest. In Parliament he at first voted with Administration, but with the Opposition on the civil list debts, 16 Apr. 1777; and henceforth he continued in opposition till the fall of North. Robinson in his survey of July 1780 noted about him: ‘of late has taken a most hostile part’. In 1780 Owen was returned unopposed for Montgomeryshire. He did not vote on Shelburne’s peace preliminaries, 18 Feb. 1783, but voted for Fox’s East India bill, 27 Nov. 1783. Robinson’s list of January 1784 and Stockdale’s of 19 Mar. classed him as ‘Opposition’. Owen was again returned unopposed at the general election of 1784. He consistently opposed Pitt’s Administration throughout this Parliament. There is no evidence of his having spoken in the House before 1790.
He died 11 Mar. 1795.