Ridley’s father was Member for Newcastle for 27 years unopposed; he himself for 38 years, unopposed after 1780; and his son and heir was Member for 24 years, all in succession. Apart from being a major Northumbrian landowner, he was a leading Newcastle entrepreneur. As owner of the Plessey collieries and of the only quay in the port of Blyth, he dominated the local coal trade until the 1790s. He was a partner in the Northumberland Glass Company at Newburn and in 1791 became a partner in the Newcastle ‘Old Bank’ (Ridley, Cookson, Widdrington, Bell & Co.). The bank had six country branches and ran a fire office and waterworks in partnership with the Exchange Bank.
Ridley had been in independent opposition to Pitt’s ministry in the Parliament of 1784 and so at first continued. He voted against their Russian policy, 12 Apr. 1791, 1 Mar. 1792, and was listed favourable to repeal of the Test Act in Scotland in April 1791. Having met with the Portland Whigs at Burlington House on 11 May 1790, he was listed one of them in December 1792. On 31 Dec. he came out in support of the aliens bill: although he had ‘frequently’ acted with opposition and would doubtless do so again, ‘he thought the country and the constitution in danger’. He attended the ‘third party’ meeting at Windham’s house on 10 Feb. 1793, though he was absent a week later. On 28 May he was of the committee to review Warren Hastings’s impeachment. On 31 May he was in the minority on Wharton’s constitutional motion. On 21 Jan. 1794 he voted with opposition against the address and on 14 Apr. against the enlistment of émigrés. On behalf of his constituents he objected to the additional duty on paper, 21 Mar. 1794. He contradicted a report of French marauding off the Northumbrian coast, 25 Mar. In 1795 and 1796 he supported all major opposition motions against the war with France and its conduct. He also opposed the seditious meetings bill, 25 Nov. 1795. He was listed ‘con’ by the Treasury. His only notable speech was in support of the Prince of Wales’s claims to the duchy of Cornwall revenues, 8 June 1795, which would ‘rescue the Prince from the odium artfully attempted to be thrown upon him on account of the extent of his debts’.
Ridley voted selectively with opposition in the Parliament of 1796: on the Bank stoppage, 28 Feb., on the exposure of Ireland to French invasion, 3 Mar., and on the mutinous sailors’ pay grievance, 10 May 1797. He objected to the landlords’ liability clause in the assessed taxes bill, 18 Apr., and stoutly opposed Pitt’s land tax redemption bill, April-May 1798, having also objected to the tax on agricultural horses, 19 Mar. He objected to rock salt imports being allowed into Scotland, but not into the northern counties, 15, 20 June. He voted against union with Ireland, 11 Feb. 1799. He was the House’s informant on the coal consumption of the metropolis when he was the coal owners’ spokesman in the debate on the coal trade, 11 Mar. 1800. He was placed on the committee of inquiry. He voted for inquiry into the failure of the Helder expedition, 10 Feb. 1800. On 25 Mar. 1801 he voted for Grey’s censure motion and on 5 June against indemnity for government informers. On 15 Mar. 1802 he defended the Tynemouth lighthouse bill. He, as before, joined opposition on the civil list question and the Prince of Wales’s claims, 29 and 31 Mar. 1802 and 4 Mar. 1803, and voted thanks for the removal of Pitt from office, 7 May 1802. He called for a double reward for Greathead, the deviser of the lifeboat, 2 June 1802.
Ridley welcomed the peace, but was in the majority of 24 May 1803 which approved the King’s message on the unsatisfactory state of negotiations with Buonaparte.
Opposition again counted on Ridley’s support in his last Parliament: but his votes and speeches were spasmodic. He rallied to them on 26 June and 6 July 1807 and was in the minorities of 14 Mar., 4 and 11 May 1808. He opposed the convention of Cintra, 21 Feb. 1809. He twice voted critically of the Duke of York’s conduct, 15 and 17 Mar. 1809, but three times came to the defence of General Clavering, who was accused of prevarication when the House heard his evidence. He voted against ministerial corruption, 25 Apr. 1809. He was delayed in the country in January, but opposed ministers on the Scheldt question, 5 and 30 Mar. 1810.
Ridley, who had retired from the corporation of Newcastle in September 1807, did not seek re-election to Parliament in 1812. He admitted that ‘the great increase of business in Parliament’ was too much for him at his ‘advanced period of life’. He had not been conspicuous in debate, but his conscientious service earned him the public plaudits of his constituents.