He held minor political offices between 1928 and 1945, notably as Parliamentary and Financial Secretary to the Admiralty from 1940 to 1945 in Winston Churchill's war-time coalition government.

[6] After Baldwin became prime minister for the third time in June 1935, Warrender was made Parliamentary and Financial Secretary to the Admiralty.

When Chamberlain reshuffled his government in early April 1940, Warrender once again became Parliamentary and Financial Secretary to the Admiralty.

Lord Bruntisfield married secondly, Tania, daughter of Dr Michael Kolin, on 22 June 1948.

They had two children: Lord Bruntisfield died in January 1993, aged 93, and was succeeded by his eldest son, John.