When David Owen became foreign secretary in 1977, he declared that human rights would have a place in government policy. But it took a small Catholic lobbying organisation and its motley group of allies – including Archbishop Óscar Romero, Cardinal Hume, assorted journalists and parliamentarians, and two political advisers funded by the Rowntrees – to make it happen

In June 1976 the British government opened negotiations to sell 15 second-hand armoured cars to the government of El Salvador, under its military president Colonel Arturo Armando Molina. The deal, valued at around £850,000, received political clearance in January 1977, with delivery scheduled for the end of the year. Molina left office in July, replaced by General Carlos Humberto Romero. Both oversaw the violent suppression of political dissent and the assassination of priests accused of subversive Marxist sympathies.

The new Archbishop of San Salvador, Óscar Romero, refused to attend his namesake’s inauguration, despite his conservative instincts, in protest against what he called the government’s “torture” of priests and its treatment of the Church. In Whitehall, meanwhile, Ministry of Defence officials busied themselves with the arrangements for shipping 12 Saladin and three Ferret scout cars, while adjusting to the changing political landscape: in February the foreign secretary, Anthony Crosland, had died suddenly and his unexpected replacement was the 38-year-old David Owen.