On 24 November 1989 Heffer announced that he would not fight the next election. The decision was prompted by the fact that he had been diagnosed with terminal stomach cancer. He suffered a long decline during which he devoted himself to writing. When Parliament was recalled to debate the invasion of Kuwait in September 1990, Heffer made what he knew would be his last speech in the House of Commons to urge the United Kingdom not to go to war. His gaunt and white appearance showed how ill he was. In January 1991 he attended the House of Commons to vote against the Gulf War in a wheelchair, when John Major crossed the floor to shake his hand. On 27 March 1991 he was awarded the freedom of the city of Liverpool, but as he was too ill to travel there, he received it at Westminster. His close friend Tony Benn attended the ceremony along with Dennis Skinner and speaker Bernard Weatherill. A letter was read out paying tribute to Heffer from John Major.