The family had been powerful in politics for several generations, and Sir Watkin effectively controlled several Parliamentary seats and led a Tory faction in the House of Commons, though he was less involved in politics than his father, and tended not to lead his faction decisively. The influence of the family had declined during his long minority. Sir Watkin was Member of Parliament (MP) for Shropshire from 1772 to 1774, and for Denbighshire from 1774 until his death in 1789 aged 39. He was criticised for poor attendance. He was Lord Lieutenant of Merionethshire from 1775 to 1789.