His involvement in the 1807 general election in Huntingdonshire and an 1809 pamphlet criticising what he saw as the nepotism of prime minister William Cavendish-Bentinck, 3rd Duke of Portland saw to it that he found no favour with the Tory establishment who were to hold power until 1830.

Grey made the appointment with such undue haste that Maltby's congé d'élire arrived in Chichester before Cornewall's funeral and the public was scandalised.

[7] On his appointment, Maltby was the sole Whig among the Lords Spiritual, save for 87-year-old Henry Bathurst, Bishop of Norwich, and he attracted much personal hostility and criticism.

His public controversies and scandals included: Maltby had strong connections to the University of Durham, making generous financial provision.

He also assisted in the negotiations of its royal charter, persuading the government to honour its undertaking to his predecessor, William Van Mildert, that all students must subscribe to the Thirty-Nine Articles before graduation.

[15][16] The Established Church Act 1836 set the maximum annual income for a bishop at £8,000 (£525,000 at 2003 prices[17]) but it was revealed in 1847 that Maltby was earning around £12,000 (£787,000[17]), having exceeded £21,000 (£1.4 million[17]) in 1841.

Prime Minister William Ewart Gladstone was appalled, denouncing the request as simony, but he eventually conceded, allowing Blomfield, now Bishop of London, to retire at the same time.