Shortly before the 1959 general election, Cliff Michelmore, Tonight’s presenter, had a hernia operation and Johnson-Smith was promoted to co-host the show for six weeks.
His profile was thus at its highest when the election was called, and on 8 October 1959 he ousted the Labour member for Holborn and St Pancras South, Lena Jeger, by 656 votes.
He successfully promoted a bill authorising councils to operate a meals-on-wheels service for the elderly and was soon on the fast track, within six months becoming PPS to ministers at the Board of Trade; in 1962 he moved to the Ministry of Pensions and National Insurance.
Sir Alec Douglas-Home quickly appointed him an Opposition whip, and when Edward Heath became leader that summer he made Johnson-Smith a party vice-chairman.
[2] Johnson-Smith, who was later to launch a successful campaign on behalf of haemophiliacs who had been given infected blood, fought a long battle to curb the Church of Scientology.
After the Bloody Sunday killings of January 1972, he mounted an uncompromising defence of the Parachute Regiment: "It is bad enough for our troops to have to run all the perils and be shot at by gunmen without having their pain increased by smears in this House."
When Margaret Thatcher took the leadership, she asked him to oversee media activities at Central Office alongside a fellow television professional, Gordon Reece.