The 70s British leader referred to in the crossword solution is Edward HEATH, who served as Prime Minister of the United Kingdom from 1970 to 1974. He was a Conservative Party politician and the first British Prime Minister to have been educated at a university. During his tenure, he oversaw the UK's entry into the European Economic Community, which later became the European Union. He also implemented a number of social reforms, including the introduction of the Industrial Relations Act 1971.