As British citizens returned Tony Blair’s “New Labor” government to 10 Downing Street for the third consecutive election, the relative weakness of the Tory opposition was highlighted by the gains made by the traditional third party in British politics, the Liberal Democrats.

As Prime Minister Blair equaled Margaret Thatcher’s historic victory total, his long-term influence on British politics is less clear. But perhaps the biggest influence on this election came from a man whose name did not appear on any ballot. In fact, he is no longer alive.

That man is Lord Roy Jenkins, longtime Labor parliamentarian, co-founder of the short-lived centrist Social Democratic Party, president of the European Commission, chancellor of Oxford University, and author of 20 books, including 2001’s magisterial biography “Churchill.”

Jenkins never succeeded in becoming prime minister himself, but his independent profile looms large over British politics today: He served as a political mentor to both Tony Blair and the Liberal Democrats’ 44-year-old leader, Charles Kennedy. Together, their revived parties in these post-Thatcher years combine for almost 60% of the British votes cast.

The son of a Welsh coal miner, Jenkins was committed to a British version of libertarian values, a mixed economy, and an internationalist approach to foreign policy. Like Churchill, he served as both home secretary and chancellor of exchequer. Jenkins drew both accolades and criticism for his actions in those offices. On the one hand, he was a social reformer who relaxed laws regarding divorce, abortion, and homosexuality, while pushing forward anti-discrimination measures on the basis of race and gender. This made him unpopular with conservatives, who accused him of ushering in a permissive society, to which Jenkins replied, “The permissive society has been allowed to become a dirty phrase. A better phrase is the civilized society.”

At the same time, he reacted to increased terrorist attacks by the Irish Republican Army in the 1970s by overseeing the strict Prevention of Terrorism Act – something of a precursor to our Patriot Act – which provided for exclusion orders and detention without charges for up to 48 hours. Left-wing activists predictably howled.

Increasingly, Jenkins found himself at odds with the socialist instincts of the old Labor Party that led them to oppose NATO and support unilateral nuclear disarmament while uncritically embracing the influence of the trade unions. In 1979, the year of Margaret Thatcher’s first election, he said, “Each successive Labor government has been the most rapacious, doctrinaire, and unpatriotic conspiracy to be seen this side of the Iron Curtain.”

Like Churchill, who left the Conservative Party for the Liberals in 1904, Jenkins moved away from Labor as a matter of principle to help form the Social Democratic Party. Their stated goal was to stand for what he called the “the radical center” of British politics by forming a broad center-left coalition comprising left Tory Party members, conservative Labor Party members, and the remnants of the then-small Liberal Party. At the time, Jenkins stated, “The politics of the left and center of this country are frozen in an out-of-date mold which is bad for the political and economic health of Britain and increasingly inhibiting for those who live within the mold.” Jenkins was the party’s prime minister-designate in the 1983 general election. One of their parliamentary candidates was the young Charles Kennedy, now leader of the Liberal Democrats. While the party ultimately crumbled, it had the effect of forcing the Labor Party to the center, especially after they suffered three consecutive election defeats under the left leadership of Neil Kinnock. The consequence is the stunning revival of the Labor Party into a potent political force and the marginalization of the Tory Party.

Jenkins’s publisher and friend Sir Harold Evans commented to me on the eve of yesterday’s elections, “Roy Jenkins was an amazingly powerful force for the shift to the center of British politics … The old militant Labor Party was a creature of the irresponsible labor unions, so the break of Jenkins was very important … If you wanted to make an algebraic equation it would be Margaret Thatcher + Roy Jenkins = Tony Blair and Charles Kennedy.”

Sir Harold added, “What’s interesting is that the Lib Dems, whose death has often been predicted, actually seem to be in a better position long-term than the Conservatives in their present form.” The once-dominant Tory Party has fallen on hard times. Mr. Blair’s ascension to the leadership represented the ultimate success of Jenkins’s more conservative wing of that party, and has directly led to this unprecedented third Labor election success. Moreover, the Labor Party has erased its reputation as incompetent stewards of the economy. And while Mr. Blair has earned the anger of left-leaning voters because of his support for President Bush and the war in Iraq, voters looking for change increasingly are turning to the Lib Dems as an alternative. The Tories have been boxed out, and their selection of three consecutive bland conservative standard bearers – William Hague, Ian Duncan Smith, and Michael Howard – have failed to win over significant numbers of new voters to the Tory cause, all to Tony Blair and the Lib Dems’ benefit. This should serve as a wake-up call.

Despite his death in 2003, Roy Jenkins’s impact endures in the person of his friends and proteges, Tony Blair and Charles Kennedy. He was ahead of his time. As Sir Harold said, “The influence of Roy Jenkins persists beyond the grave, which would have pleased him as an eminent biographer.”