Leeds was a Member of Parliament for Eye in 1774 and for Helston from 1774 to 1775; in 1776 having received a writ of acceleration as Baron Osborne, he entered the House of Lords, and in 1777 Lord Chamberlain of the Queen's Household and Captain of Deal Castle.
Subsequently Leeds took little part in politics: in 1792, hearing rumours that a new coalition might be formed, he unwisely offered himself as its head and met with a firm rebuff from both Pitt and the King [REF].