‘One of the most active and essential functionaries of the central government’, Robinson’s last effective political action was his desertion of Lord North in favour of Pitt in 1783, for which he was rewarded with a peerage for his son-in-law’s father, Lord Abergavenny, and a place for himself. North forgave Robinson on his deathbed. During the Regency crisis he had shown himself to be a vicar of Bray. It was as a superannuated secretary to the Treasury that he continued to represent Harwich, where he was high steward, until his death. Listed among opponents of repeal of the Test Act in Scotland in 1791, he took no further part in politics, however, beyond an insistence on being kept informed of what was going on and a refusal to retire: in 1796, when Henry Dundas showed an interest in his making way for somebody else, Robinson prevaricated and, although his health was poor throughout this period and his attendance infrequent, he paired and held on. If present, he disturbed the most impassioned speeches by snoring loudly.
His person was coarse, inelegant, and somewhat inclined to corpulency, but he possessed solid judgment, and suavity of temper, combined with plain, unaffected, and conciliating manners, was capable of great application as well as of steady friendship, and by no means wanted decision of character.
Wraxall Mems. i. 428.