Staking his claim to the future leadership of the party yesterday with a highly Euro-sceptic attack on Britain's European partners for proposing a common defence policy, the speech produced the longest standing ovation of the day.
Mr Portillo, Secretary of State for Defence, raised the spectre of the European Commission seeking to harmonise or "even metricate" uniforms and cap badges in a European common defence force.
He also passionately defended the Special Air Service and lambasted the condemnation by the European Court of Human Rights of the Gibraltar killings. He said the Tories sent a clear message to the European Court: "Don't give comfort to terrorists."
His tirade had the hall clapping and stamping its feet for more and eclipsed the appeal of John Redwood, the former right-wing challenger for the leadership. There were hisses when Mr Portillo mentioned Brussels. "It would be absurd, as some of our partners are urging, to try to merge our defence co-operation into the European Community," he said.
Malcolm Rifkind, the Foreign Secretary, who also adopted a Euro-sceptical tone in the foreign affairs debate, promoted closer co-operation on defence with European partners, particularly the French, when he was defence secretary.
Mr Portillo declared: "There are those in the Labour Party and across Europe sleepwalking their way along the dreamy road to a European superstate. We will not allow Brussels to control our defence policy. With a Conservative government Britain will not join a single European Army."
But there is little threat of a common defence policy - proposed by Jacques Delors, the past president of the European Commission - being pushed by the French and the Germans for the inter-governmental conference next year.
Britain has led pressure for the Western European Union - formed in 1948 - to be the focus for European defence, outside the European Union.
Mr Rifkind said any further erosion of sovereignty would be judged on "whether there would be such benefit to the prosperity, to the security, or to the quality of life of the British people".
Labour's readiness to go along with what the majority of other countries wanted was the "new fault line in British politics", he said. After announcing the objective of a new Atlantic community, Mr Rifkind told reporters that while France remained "protectionist", he had secured significant allies among other member states.Reuse content