After studying law at Glasgow under the radical Whig Professor John Millar, Anstruther, at the outset of a successful career at the English bar, became active in East India Company affairs, and in October 1782 as a member of the court of proprietors made an effective speech (subsequently printed) strenuously opposing the Commons resolution for the recall of Warren Hastings, whose administration he defended as mild, just and upright.
In December 1783, shortly before the fall of the Coalition, Robinson wrote:
Mr. Anstruther at present takes the line of support of Government because he holds an office, but, if a change, in a future Parliament would, it is believed, support as he does now.
But Anstruther remained opposed to Pitt, and at the general election of 1784 Henry Dundas sponsored a Government candidate against him. Nevertheless, John Anstruther was returned.
In the new Parliament he became a leading Opposition speaker, specializing in East India affairs and legal issues. On 4 Aug. 1784 he for once joined forces with Dundas to oppose, on behalf of his Scottish constituents, the duty on printed linens, commenting upon ‘the dangerous spirit of emigration excited among the manufacturers’.
A consistent opponent of reform, he rebutted the claim made on 23 May 1787 that Francis Charteris was not required to vacate his seat on becoming the eldest son of a Scottish peer, and when Lord Maitland threatened to bring in a bill to put English and Scottish peers’ sons on a footing of equality, declared: ‘It behoves the representatives of the boroughs and counties of Scotland and also ... of England to reflect seriously before they gave consideration to any bill, the object of which was to alter the Act of Union.’
By this time he was aware that he would not be re-elected for Anstruther Burghs. The Opposition survey of the ‘Political State of Scotland 1788-9’ records:
He died 26 June 1811.
