He saw active service as a Lieutenant-Commander in the Royal Naval Volunteer Reserve during the Second World War.

[1] Watkinson was elected Member of Parliament (MP) for the new constituency of Woking, Surrey in 1950, holding the seat until 1964,[2] and was initially Parliamentary Private Secretary (PPS) to the Minister of Transport and Civil Aviation, John Maclay, from 1951 to 1952.

He became a government member under Winston Churchill as Parliamentary Secretary to the Ministry of Labour and National Service in 1952, a post he held until December 1955,[1] when he was made Minister of Transport and Civil Aviation by Sir Anthony Eden, entering the cabinet in January 1957,[1] and remaining there when promoted to Minister of Defence under Harold Macmillan in 1959.

Watkinson was one of seven cabinet ministers sacked in July 1962 in Macmillan's Night of the Long Knives.

[3] He was appointed a Privy Counsellor in 1955, a Member of the Order of the Companions of Honour in 1962,[4] and raised to the peerage as Viscount Watkinson, of Woking in the County of Surrey, in 1964.