Bayntun Rolt succeeded to an estate of nearly £3,000 p.a., carrying a major interest at Chippenham. Returned at a by-election in 1737 he joined the Whig Opposition, voting against the Government on the Spanish convention in 1739. He was re-elected in 1741 with another opposition candidate, Sir Edmund Thomas, against two government candidates, whose petition was treated as a trial of strength between Walpole and his opponents. When on 28 Jan. 1742 a minor point in connexion with it was carried against the Government by one vote, both sides accepted it as decisive.
While the tellers were performing their office, [Sir Robert] beckoned Sir Edward Bayntun ... to sit near him, spoke to him with great complacency, animadverted on the ingratitude of several individuals who were voting against him, on whom he had conferred great favours, and declared he should never again sit in that House.
Coxe, Walpole, i. 695.
After Walpole’s fall, Bayntun Rolt voted with the Government. Mentioned as a possible lord of Trade in November 1743,
