Shaw Stewart inherited through his mother great wealth and property which, added to his father’s interest, gave him a leading position in Renfrewshire politics. Described by Boswell as a ‘lively, good-natured, rattling’ young man,
A man of independent views on religion and politics,
Noted more for his roistering social life than parliamentary ability, Stewart made little impression in the House. He did not vote either on Lowther’s motion against the war, 12 Dec. 1781, or on the censure of the Admiralty, 20 Feb. 1782, but from 22 Feb. voted with the Opposition in every recorded division until the end of North’s Administration. He voted against Shelburne’s peace preliminaries on 18 Feb. 1783, and for parliamentary reform on 7 May. The Coalition lost a supporter when Stewart, in fulfilment of his electoral bargain, vacated his seat in July to make way for William McDowall jun., who sat until June 1786 when, on the expiration of his stipulated term, he in turn applied for the Chiltern Hundreds.
The compact was now at an end; at the by-election McDowall contested the seat as a Pitt supporter, Shaw Stewart as a Foxite. After a protracted struggle Stewart was returned; McDowall petitioned, but withdrew his objections when countercharges were made that Charles McDowall, the sheriff depute, had deliberately delayed the election date in his kinsman’s interest. On 17 Apr. 1787 William Adam moved that the sheriff attend at the bar of the House to answer the charge, and was supported by Shaw Stewart, who humourously recounted, in his only reported speech, the ‘many passages’ between the sheriff and himself over the election. ‘The House was highly entertained and laughed heartily.’
Stewart remained an inconspicuous member of the Opposition with whom he voted on the Regency. William Adam, in his Political State of Scotland in 1788-9, wrote (pp.278-9):
Mr. Shaw Stewart’s character is acknowledged by men of all parties to be full of benevolence and good sense. He is a man of very independent principles and is understood to be sincerely attached to the Duke of Portland.
He died 7 Aug. 1812.
