In the House of Lords he joined the party hostile to Sir Robert Walpole, took a fairly prominent part in public business, and earned the dislike of George II. When Carteret, now Earl Granville, resigned office in November 1744, Bedford became First Lord of the Admiralty in the administration of Henry Pelham, and was made a privy councillor. He was very successful at the admiralty, but was not equally fortunate after he became Secretary of State for the Southern Department in February 1748. Pelham accused him of idleness; he was constantly at variance with his colleague the Duke of Newcastle, and resigned office in June 1751.
Instigated by his friends he was active in opposition to the government, and after Newcastle’s resignation in November 1756, became Lord Lieutenant of Ireland in the ministry of William Pitt and the Duke of Devonshire, retaining this office after Newcastle, in alliance with Pitt, returned to power in June 1757. In Ireland he favoured a relaxation of the penal laws against Roman Catholics, but did not keep his promises to observe neutrality between the rival parties, and to abstain from securing pensions for his friends. His own courtly manners and generosity, and his wife’s good qualities, however, seem to have gained for him some popularity, although Horace Walpole says he disgusted everybody. In March 1761 he resigned this office.
Having allied himself with the Earl of Bute and the party anxious to bring the Seven Years War to a close, Bedford was noticed as the strongest opponent of Pitt, and became Lord Privy Seal under Bute after Pitt resigned in October 1761. The cabinet of Bute was divided over the policy to he pursued with regard to the war, but pacific counsels prevailed, and in September 1762 Bedford went to France to treat for peace. He was considerably annoyed because some of the peace negotiations were conducted through other channels, but he signed the Peace of Paris in February 1763. Resigning his office as Lord Privy Seal soon afterwards, various causes of estrangement arose between Bute and Bedford, and the subsequent relations of the two men were somewhat virulent. The duke refused to take office under George Grenville on Bute’s resignation in April 1763, and sought to induce Pitt to return to power. A report, however, that Pitt would only take office on condition that Bedford was excluded, incensed him and, smarting under this rebuff, he joined the cabinet of Grenville as Lord President of the Council in September 1763. His haughty manner, his somewhat insulting language, and his attitude with regard to the regency bill in 1765 offended George III, who sought in vain to supplant him, and after this failure was obliged to make humiliating concessions to the ministry. In July 1765, however, he was able to dispense with the services of Bedford and his colleagues, and the duke became the leader of a political party, distinguished for rapacity, and known as the “ Bedford party,” or the “ Bloomsbury gang.”
During his term of office he had opposed a bill to place high import duties on Italian silks. He was consequently assaulted and his London residence attacked by a mob. He took some part in subsequent political intrigues, and although he did not return to office, his friends, with his consent, joined the ministry of the Duke of Grafton in December 1767. This proceeding led "Junius" to write his "letter to the duke of Bedford," one of especial violence. Bedford was hostile to John Wilkes, and narrowly escaped from a mob favourable to the agitator at Honiton in July 1769.
His health had been declining for some years, and in 1770 he became partially paralysed. He died at Woburn on 5 January 1771, and was buried in the family burying-place at Chenies. His three sons all predeceased him, and he was succeeded in the title by his grandson, Francis.
The duke held many public offices: lord-lieutenant of Bedfordshireshire and Devonshire, and chancellor of Dublin University among others, and was a knight of the garter. Bedford was a proud and conceited man, but possessed both ability and common-sense. The important part which he took in public life, however, was due rather to his wealth and position than to his personal taste or ambition. He was neither above nor below the standard of political morality of the time, and was influenced by his duchess, who was very ambitious, and by followers who were singularly unscrupulous.
| Preceded by: Wriothesley Russell | Duke of Bedford | Followed by: Francis Russell |