Estcourt was returned for Devizes on the interest created by his late father-in-law, in succession to Henry Addington, his wife’s uncle. He took his seat on 28 Jan. 1805. His father had informed Lord Sidmouth (as Addington now was) three days before:
Although he has obtained thus early and honourably that which many others seek with so much anxiety, I am sure he never will forget to whom he is primarily indebted for it as well as his most peculiarly happy domestic blessings. He must ever consider your interests at Devizes and those of New Park as inseparable ... If at a future time we should have reason to think there may be a hazard in attempting to carry both seats, he will think it his duty to act in such a way as shall throw the whole weight of his influence whatever it may be into your scale.
Sidmouth mss.
Estcourt showed his attachment by deserting Pitt with the Addingtonians and voting in favour of the criminal prosecution of Melville, 12 June 1805: he was duly listed ‘Sidmouth’ a month later. Sidmouth being in office, he also voted for the Grenville ministry’s repeal of Pitt’s Additional Force Act, 30 Apr. 1806; but was adverse to their abolition of the slave trade, voting with the die-hards, 6 Mar. 1807. At that time he hoped to represent his county on a future vacancy, his father encouraging him to believe that he would prove an acceptable candidate in North Wiltshire; but he was disconcerted to discover that his friend John Hungerford Penruddocke and two others had the same pretensions.
My political connections are most anxious to support the King, and by no means to enter into a systematic opposition. In these leading points you I believe agree with us. In the minor points we cannot disagree.
Ibid.
Sidmouth did not obtain office under Portland in 1807 and Estcourt joined him in opposing the Copenhagen expedition, 3 Feb. 1808. He was described as well disposed to the claims of John Palmer for compensation.
Estcourt was listed a Treasury supporter in the Parliament of 1812. Nevertheless he opposed the revision of the Corn Laws almost throughout in 1815.
Estcourt was admitted even by such opponents as the radical Henry Hunt to be ‘manly, honest, candid and honourable. He was far too much of a gentleman and man of honour to disgrace himself by falsehood or by giving his silent consent to the misrepresentations of others.’
