[1][2] In the 1768 general election Buller was returned unopposed as Member of Parliament for Exeter on the corporation interest.
Some time before 1774, probably on the death of his half-brother James in 1772, Buller took over the management at West Looe constituency, where he was able to arrange the return of two Members.
He stood at Cornwall in order to draw votes away the opponents of his brother in law William Lemon and came third, but he was returned as MP at Launceston.
His involvement at Saltash in the 1784 election was on behalf of John Lemon who after petitions and disputes about voting rights was eventually returned in 1787.
In the 1790 general election Buller did not stand but was able to return Government supporters both at Saltash and at West Looe.