Miliband wrote a rebuttal defending his dad, who came to Britain as a teenage refugee from the Nazis and served with the Royal Navy in World War II. "I loved him and he loved Britain," Miliband wrote of his father, who died in 1994. "I know they say 'you can't libel the dead,' but you can smear them."
The paper's attack has won Miliband wide sympathy, and has brought the rare spectacle of politicians from all parties criticizing the Daily Mail.
Former Conservative Cabinet Minister Michael Heseltine accused the Mail of "carrying politics to an extent that is just demeaning."
Deputy Prime Minister Nick Clegg, a Liberal Democrat, said Thursday that "if anyone excels in denigrating and often vilifying a lot about modern Britain, it's the Daily Mail."
Clegg had a point - the Mail exudes a deep ambivalence about British society. Its successful formula is to offer readers a mix of anxiety and reassurance, spiced with a dash of sex.
Journalism professor and Guardian media columnist Roy Greenslade said the Mail is often described as the paper that "speaks for Middle England - that segment of the working class which has middle-class aspirations and wishes to defend them against all comers."
"It is vaguely anti-immigrant. It has opposed in the past social liberal moves such as gay rights," he said.
Among the things the Mail approves of are British troops, hardworking "mums and dads" and cute domestic animals. It dislikes unemployed "benefit scroungers" - especially if they're immigrants - Brussels bureaucrats, badly behaved celebrities and left-wing politicians like Ed Miliband.
In the newspaper's pages, common foods regularly turn out to cause cancer - or obesity - and climate change is treated with skepticism.
One recent headline had scientists saying "Global warning just half what we said," while another read "World's top climate scientists confess: Global warming is just quarter what we thought." Another article this week said global warming was "on pause."
Now the Mail itself has become the story.
The furor began Saturday with the article excoriating Ralph Miliband for his Marxist views. It flared again on Thursday when Ed Miliband wrote to Lord Rothermere - chairman of the paper's owner, Daily Mail and General Trust PLC- complaining that a reporter from the Daily Mail's Sunday sister paper had showed up at his uncle's memorial service this week and tried to interview mourners.
Mail on Sunday editor Geordie Greig quickly apologized for the "terrible lapse of judgment." In contrast, Daily Mail editor Paul Dacre has been silent, though he dispatched a deputy to defend the story on television.
It is unwelcome attention for the publicity-shy, 64-year-old Dacre, the Mail's editor since 1992. He has built the paper into a powerful media institution, with a circulation of 1.8 million, second only to the Rupert Murdoch-owned Sun among Britain's daily newspapers. The Mail's website - light on politics, heavy on celebrity snapshots - is one of the most widely read news sites in the world.
Even the paper's critics acknowledge its skill at understanding what readers want, and its campaigning energy - it waged a long fight to bring to justice the racist killers of black teenager Stephen Lawrence, a notorious murder case.
And even those who call the paper the "Hate Mail" have helped secure its place in popular culture.
A popular online quiz asks "Does the Daily Mail Hate You?" Factors include being a woman and having parents born outside the U.K. There's also the "Daily Mail-o-matic" headline generator - click a button and it throws together phrases such as "Could Muslims ruin pensioners?" and "Are feral children giving Britain's swans diabetes?"
Now this powerful media player is on the defensive. Opponents have pointed out that the Mail supported the Nazis during the 1930s, and Labour lawmaker John Mann - chair of Parliament's all-party group against anti-Semitism - said the newspaper's attack on Ralph Miliband, who was Jewish, smacked of "the classical age old anti-Semitic smear about disloyal Jews."
Calls for an advertising boycott have been backed by Labour figures including former Deputy Prime Minister John Prescott.
And the furor has reanimated a debate about press regulation that has been swirling since the scandal over tabloid phone hacking. The Mail has not been implicated in hacking, but Dacre, like other newspaper editors, strongly opposes any form of state regulation.
Bob Satchwell, executive editor of the Society of Editors, said he hoped the Miliband affair would not trigger restrictions on the press.
"If you've got a free press it must be free to express itself," Satchwell told Sky News.
- AP