British nationalist viewpoint, he sided strongly with the Ulster Unionists in their desire to remain a constituent part of the United Kingdom. From early 1971, he opposed, with increasing vehemence, Heath's approach to Northern Ireland, the greatest breach with his party coming over the imposition of direct rule in 1972. He strongly believed that it would survive only if the Unionists strove to integrate completely with the United Kingdom by abandoning devolved rule in Northern Ireland. He refused to join the Orange Order, the first Ulster Unionist MP at Westminster never to be a member (and, to date, one of only four, the others being Ken Maginnis, Danny Kinahan and Sylvia Hermon), and he was an outspoken opponent of the more extremist loyalism espoused by Ian Paisley and his supporters. In the aftermath of the Birmingham pub bombings by the Provisional Irish Republican Army (PIRA) on 21 November 1974, the government passed the Prevention of Terrorism Act. During its second reading, Powell warned of passing legislation "in haste and under the immediate pressure of indignation on matters which touch the fundamental liberties of the subject; for both haste and anger are ill counsellors, especially when one is legislating for the rights of the subject". He said terrorism was a form of warfare that could not be prevented by laws and punishments but by the aggressor's certainty that the war was impossible to win. When Heath called a leadership election at the end of 1974, Powell claimed they would have to find someone who was not a member of the Cabinet that "without a single resignation or public dissent, not merely swallowed but advocated every single reversal of election pledge or party principle". During February 1975, after winning the leadership election, Margaret Thatcher refused to offer Powell a Shadow Cabinet place because "he turned his back on his own people" by leaving the Conservative Party exactly 12 months earlier and telling the electorate to vote Labour. Powell replied she was correct to exclude him: "In the first place I am not a member of the Conservative Party and secondly, until the Conservative Party has worked its passage a very long way it will not be rejoining me". Powell also attributed Thatcher's success to luck, saying that she was faced with "supremely unattractive opponents at the time". During the 1975 referendum on British membership of the EEC, Powell campaigned for a 'No'