In 1970 he became Chancellor of the Duchy of Lancaster under Edward Heath, and being in favour of the Common Market was given the responsibility of negotiating Britain's entry into it.

During his tenure the Department of the Environment was housed on Marsham Street in unattractive tower blocks nicknamed 'the three ugly sisters'.

He was at one time a prominent member of the Conservative Monday Club, for whom he authored a booklet entitled Right Angle, and was guest-of-honour at their Annual Dinner in 1970.

The Club was, however, divided on the EEC (European Community) issue, and at their conference in October 1971 members moved and carried a resolution opposing Britain's entry.

He was created a life peer on 5 October 1987 taking the title Baron Rippon of Hexham, of Hesleyside in the County of Northumberland.