While still a minor Glynne married the heiress to the estates of two leading Flintshire families, thus acquiring a claim to share the local parliamentary representation with the Mostyns. After contesting Flint Boroughs unsuccessfully in 1734, he was returned unopposed for the county in 1741 as a Tory, voting consistently against the Government and speaking against the Hanoverians in January 1744. A few weeks later he assured Hardwicke, in connexion with the appointment of Flintshire J.P.s that ‘no endeavours shall ever be wanting in me to render to his Majesty and to his Government all the services in my little power’;
On retiring from the county seat in 1747 Glynne gave it out that he did not intend to stand for Parliament again, but in 1753 he took advantage of an opportunity to be returned for Flint Boroughs without opposition, continuing to represent them at little expense till his death, 1 June 1777.
