Osborne had a ‘miraculous escape’ from shipwreck in the Baltic while on his tour of the northern courts with Lord Talbot in the winter of 1797. When he came of age, he was expected to be returned for the family borough of Helston by his father, Pitt’s former Foreign secretary, who had gone over to opposition in 1791. Both Members for Helston duly proffered their resignation to the duke in October 1798; his reply was ‘unless he has very lately changed his mind [I] believe he would as soon wish for a seat in the stocks as one in Parliament’. By December, Osborne had changed his mind and it was settled that Richard Richards should make way for him. On 31 Jan. 1799 his father died. His brother the 6th Duke now announced his adhesion to Pitt’s government. On 4 Apr. 1799 Charles Abbot, the other Member for Helston, introduced Osborne to the House of Commons, five days after his election.
No vote of Osborne’s against Addington’s ministry is known until April 1804. He was in Fox’s minority on defence on 23 Apr., joined Brooks’s on 23 June and was listed among the opposition by Pitt’s calculators in September 1804 and July 1805. His voting behaviour confirmed this. He supported his friends in power in 1806, appearing in their majority for the repeal of Pitt’s Additional Force Act on 30 Apr. In October he attended Fox’s funeral, Lord Holland being informed by Lord John Townshend that Osborne ‘had no other politics but his respect and regard for our dear friend, to whom (though he had no personal intercourse with him) he was most sincerely and faithfully attached’.
I am sick of politics if our progressive steps towards certain ruin can be so called. The emigration of the House of Braganza is a great event. Why should not the House of Brunswick imitate so noble an example and transport themselves with ... all the ministers and the German Legion to Botany Bay?
Add. 34457, f. 390.
In 1810, thanks to the initiative of a freelance Whig agent John Goodwin, Osborne became the Whig candidate against Charles Philip Yorke, the unpopular ministerial Member for Cambridgeshire, who was seeking re-election. His property qualification was of the slightest: a ‘shooting box’ afterwards enlarged; but unlike other contenders, he was sufficiently known, ready to risk a contest and acceptable to the Whig grandees. Lord Hardwicke, also in opposition, clinched matters by promising to support Osborne if his brother stood down, and when that happened he was returned unopposed. The Whigs were jubilant and no sooner had Osborne taken his seat than he launched into an attack on the conduct of the Scheldt expedition, 29 Mar. 1810. He remained ‘strong in opposition’, but never shone in debate. His only other known speeches in that Parliament were against the Regency proposals, 2 Jan. 1811, a speech which elicited a courteous reply from his vanquished opponent Yorke, and against the diplomatic pensions bill, 5 Apr. 1811: he wished the ‘brave’ army officers were as well provided for. He voted for parliamentary reform, 21 May 1810, as also in 1817 and 1819. He was equally staunch in favour of sinecure reform and Catholic relief. His attendance record was good, but at times he required nudging: Lord Auckland prompted him. In April 1818 he was one of eight Whig defaulters at Newmarket who did not come up to oppose the ducal grants, though he was present to vote against the Duke of Kent’s on 15 May. He was open to persuasion: on 22 Apr. 1814 he supported the reprimand of the Speaker moved by Morpeth after being swayed by the debate.
Osborne retained his county seat until shortly before his Whig friends raised him to the peerage.
