An advanced Liberal, he was appointed Solicitor General in 1916, receiving the customary knighthood, and was sworn of the Privy Council in 1918.

On the resignation of the Earl of Reading as Lord Chief Justice of England in 1921, Hewart asked to succeed him.

He worked closely with his Irish counterpart, Hugh Kennedy in May 1922 to finalise the text in time for elections the following month.

[2] In 1929, Hewart published The New Despotism, in which he asserted that the rule of law in Britain was being undermined by the executive at the expense of the legislature and the courts.

[3] This book was very controversial[4] and led to the appointment of a Committee on Ministers' Powers—chaired by the Earl of Donoughmore—but its Report rejected Hewart's arguments.