Finally, our leaders are outraged. The claim that the mobile phone of the murdered teenager Milly Dowler was hacked by the News of the World has been described as "truly dreadful" (David Cameron), "totally shocking" (Ed Miliband) and "grotesque" (Nick Clegg). Could this be the moment that Britain's spineless politicians begin to break free from the pernicious grip of the Murdoch media empire?

In recent years, there has been no more sickening - and, I should add, undemocratic - spectacle in British public life than that of elected politicians kneeling before the throne of King Rupert. Paying homage in person to the billionaire boss of News Corporation became almost a rite of passage for new party leaders. Tony Blair, famously, flew out to address News Corp's annual conference on an island off Australia in 1995. "We were thrilled when Tony was invited to be the keynote speaker," writes Blair's ex-chief of staff, Jonathan Powell, in his memoir.

The day after his speech in front of the media mogul, an editorial in the Murdoch-owned Sun declared: "Mr Blair has vision, he has purpose and he speaks our language on morality and family life." By 1997, the Sun - which had heaped such abuse and ridicule on the former Labour leader Neil Kinnock - had officially come out for Blair and, in the wake of his landslide election victory, the new prime minister thanked the Sun for its "magnificent support" that "really did make the difference".

But it didn't. "I think the Sun came out for us because they knew we were going to win," says Blair's former communications chief, Alastair Campbell, now. In a study for the Centre for Research into Elections and Social Trends in 1999, Professor John Curtice of the University of Strathclyde concluded that it "was not the Sun wot won it in 1997", adding: "[T]he pattern of vote switching during the campaign amongst readers of the Sun or any other ex-Tory newspaper proved to be much like that of those who did not read a newspaper at all."

Rupert and friends

Yet Blair - and, lest we forget, Gordon Brown - continued to hug Murdoch close. "He seemed like the 24th member of the cabinet," the former Downing Street spin doctor Lance Price has observed. On issues like crime, immigration and Europe, "his voice was rarely heard . . . but his presence was always felt". Little has changed under Cameron. He appointed Andy Coulson as his director of communications in July 2007 - just six months after the latter had resigned as News of the World editor over the original phone-hacking scandal.

The Tory leader then made his own pilgrimage to the see the Sun King in August 2008, joining Murdoch on his yacht off the coast of Greece. It is said that he removed the liberal Dominic Grieve as shadow home secretary in 2009, on the insistence of News International's chief executive - and close personal friend - Rebekah Brooks, who is now under pressure to quit over her alleged role in the hacking affair. The Culture Secretary, Jeremy Hunt, waved through proposals to allow Murdoch to buy all of BSkyB - in the midst of the hacking row.

Why has the political class been seduced by Murdoch? Fear? Deference? Awe of his wealth and power? Murdoch, it is often remarked, spots and backs winners - but nowadays he seems to have lost his Midas touch. In September 2008, the Murdoch-owned New York Post enthusiastically endorsed John McCain, who was defeated by Barack Obama two months later. In September 2010, the Sun came out in favour of David Cameron, who failed to win a parliamentary majority less than than nine months later. "I think the Murdoch press has less influence than it used to," the Labour leader, Ed Miliband, told me in August 2010 in the midst of his leadership campaign. "I don't think the Sun had a particularly good election. Twenty-three front pages supporting the Tories and the Tories got 36 per cent of the vote."

Corp values

Since becoming leader, however, Miliband has sent out mixed signals. In December, he hired the ex-Times journalist Tom Baldwin as his chief spinner. Baldwin would later warn shadow cabinet ministers against linking Murdoch's bid for BSkyB to the phone-hacking scandal and "against anything which appears to be attacking a particular newspaper group out of spite". In April, in a cringe-inducing interview with the Sun, Miliband proclaimed: "I will stand. . . for Sun readers and for their concerns."

And, on 16 June, Miliband arrived at News International's summer party to meet Murdoch for the first time. Shamefully, senior Labour figures - including Ed Balls, Yvette Cooper, Douglas Alexander and the Miliband aides Tom Baldwin and Stewart Wood - outnumbered Tory ministers at the bash.

Then again, Miliband was the first party leader to call for a review of newspaper regulation, after the News of the World admitted to phone hacking in April. He was the first leader to call for a public inquiry into hacking in the wake of the Dowler allegations, and the only party leader to call for Brooks to stand down. In a bravura performance at Prime Minister's Questions on 6 July, Miliband also insisted that News Corp's bid for BSkyB should now be referred to the Competition Commission.

These are encouraging moves that friends say he will not be backing away from. The summer party notwithstanding, Miliband has made it clear that he is the first party leader in a generation who doesn't necessarily quiver at the mention of Murdoch's name. "Ed has made it clear to national newspaper editors that he is going to be his own man and engage with them without fear or favour," says a close ally of his.

Murdoch's poisonous influence on UK politics has to be challenged. If not now, when? If not Ed Miliband, the candidate of "change" and "moving on" from New Labour, then who?