On his father’s retirement in 1812 Ridley succeeded him unopposed as Member for Newcastle. A few months later he came into his inheritance, which combined extensive landed property with coal mining, industrial and banking interests. He became senior partner in the bank of Ridley, Bigge & Co. of Newcastle. He was a committed Whig and unlike his father became a keen debater, who after 1815 rarely missed a division. He joined Brooks’s Club on 10 Mar. 1813. That session and subsequently he supported Catholic relief. In his maiden speech he gratified his constituents by opposing any alteration to the Corn Laws, 5 May 1814:
Corn was the regulator of the price of all articles and commerce: if the price of corn was raised, the price of labour would be raised also, and then the advance in the price of our manufactures might ensue: this might have the effect of driving them from those markets where they had hitherto been unrivalled. It would destroy a means of national wealth; and if it should induce any of our manufacturers to emigrate to other countries, the number of consumers would be diminished, and the landed interest would essentially suffer.
Privately he was of opinion that some degree of protection would not be so injurious as his constituents supposed. He proceeded to modify his views and on 23 Feb. and 8 Mar. 1815 his only objection against protection was that the duty proposed on imported corn was too high: but he withdrew his amendment to that effect. On 8 Mar. he justified his views and on the 10th voted with the minority, on the same principle. There was some dissatisfaction in his constituency, although he had warned the stewards of the incorporated companies of Newcastle of his stance, and he had to rebut charges that he was consulting his own interest only.
On other subjects Ridley was not equivocal: on 20 June 1814 he acted with Whitbread in what the Speaker described as ‘a violent and angry debate on the alleged rupture of the treaty of marriage between the Princess Charlotte of Wales and the hereditary Prince of Orange’.
At his re-election in 1818, which was unopposed although he rushed to Newcastle in anticipation of a contest, Ridley defended his record as a champion of ‘the privileges of the people ... a rigid economy in public expenditure ... friendly to moderate reform’. His agricultural protectionism still rankled and he admitted that Newcastle had not benefited from the opening up of the East Indian trade; but he claimed credit for his efforts to prevent the establishment of a customs house at Shields, which was resented at Newcastle.
Ridley was respected by his fellow opposition Members, particularly by the northern Whigs, and even spoken of as leader of the opposition after Ponsonby’s death, but only after the reported refusal of three others.
On 18 Mar. 1819 Ridley revived his attack on the junior lordships of Admiralty in which he promised to persevere, after being defeated by 245 votes to 164. On 2 June he proposed that that board should have one secretary instead of two. He continued to advocate retrenchment in other respects. On 2 June his attack on the naval estimates was repelled by 164 votes to 97, and on 8 June, when he protested against the proposed indirect taxes ‘on articles of the most general consumption’ in a time of popular distress, his amendment was defeated by 186 votes to 76. After giving a pre-sessional dinner to the northern Whigs, he supported Althorp’s motion for a committee on the state of the country, 30 Nov. 1819, claiming that ‘the country now looked up to the opposition, with the utmost confidence, on account of the resistance which they had given to the late and the present most mischievous acts of government’. He had not been sanguine about a county meeting of protest in Northumberland, and Lambton, writing to Lord Grey, hinted that he was lacking in zeal on the subject. He nevertheless spoke cautiously against repressive legislation. He opposed the newspaper stamp duties bill, 1 Dec. He deprecated alarmism about public meetings in his constituency, 3, 9 Dec. The bill against seditious meetings ‘should be strictly confined to the necessity of the case’, both as to duration and application, 8 Dec. The seizure of arms bill was necessary, but he could not accept the clause empowering search by night, 14 Dec. He voted against it again next day, but seems to have been absent thereafter. In January 1820 he supported a Newcastle reformers’ meeting. He died 14 July 1836, ‘a sincere and practical reformer’.
