Hayter was discovered drowned in a small lake in the grounds of his Berkshire residence following a bout of depression. In his 28 years as an MP he was only obliged to face a contested election once, in 1852, being otherwise unopposed six times. He was a Liberal whip and held several government posts including financial secretary to the Treasury and Parliamentary and patronage secretary. He voted for the repeal of the Corn Laws and was present at all the divisions in favour of free trade. He was succeeded as baronet by his son Arthur Divett Hayter, Baron Haversham (1835-1917) who also became a Liberal MP and whip.