Ed Miliband has accused the Daily Mail of smearing his father as "the man who hated Britain", insisting his dad owed his life to the country.

The Labour Party leader said Ralph Miliband, a Jew who fled Belgium aged 16 to escape the Nazis, loved and served Britain and also taught both his sons to do the same.

In a two-page essay printed in Saturday's edition of the Daily Mail headlined "the man who hated Britain", Geoffrey Levy examined the political beliefs of Marxist academic Ralph and how that influenced his two sons.

It questioned what Ralph Miliband, who died in 1994, "really" believed in, adding "the answer should disturb everyone who loves this country".

Mr Miliband took the unusual step of using Twitter to express his anger about the piece and revealed the Daily Mail had agreed to publish a response from him in today's edition.

In his reply, Mr Miliband said it was "absurd" to build a case about him hating Britain on an adolescent diary entry.

The Daily Mail had quoted the 17-year-old Ralph writing that the Englishman is a "rabid nationalist" and "you sometimes want them almost to lose (the war) to show them how things are".

But the Opposition leader said fierce debate about politics did not justify "character assassination" of his father.

Mr Miliband said his dad would have been amused and disappointed in equal measure by the paper's claims his son was part of some "sinister" Marxist plot because he would have known the claim was "ludicrously untrue".

There is no credible argument in the article or evidence from his life to justify the "lurid headline" or the claim it would "disturb everyone who loves this country", Mr Miliband added.

In his response, he wrote: "Like most refugees, the security of our country was really important to him. And like some refugees, he owed his life to it. So my Dad loved Britain, he served Britain, and he taught both David and me to do the same."

Mr Miliband said he accepted politicians needed to be held to account but what appeared in the Daily Mail on Saturday "was of a different order altogether".

He said: "I know they say 'you can't libel the dead' but you can smear them.

"Fierce debate about politics does not justify character assassination of my father, questioning the patriotism of a man who risked his life for our country in the Second World War or publishing a picture of his gravestone with a tasteless pun about him being a 'grave socialist'.

"The Daily Mail sometimes claims it stands for the best of British values of decency.

"But something has really gone wrong when it attacks the family of a politician - any politician - in this way. It would be true of an attack on the father of David Cameron, Nick Clegg, or mine.

"There was a time when politicians stayed silent if this kind of thing happened, in the hope that it wouldn't happen again.

"And fear that if they spoke out, it would make things worse. I will not do that. The stakes are too high for our country for politics to be conducted in this way. We owe it to Britain to have a debate which reflects the values of how we want the country run."

Mr Miliband described how his father arrived in Britain from Belgium after walking 100 kilometres with his dad to catch one of the last boats out before German soldiers arrived.

Four years later, a 20-year-old Ralph joined the Royal Navy and fought the Nazis for his adopted country as part of the D-Day landings in Normandy in June 1944.

On why his father joined the navy, Mr Miliband added: "He did so because he was determined to be part of the fight against the Nazis and to help his family hidden in Belgium. He was fighting for Britain."

Mr Miliband also wrote: "Whatever else is said about my Dad's political views, Britain was a source of hope and comfort for him, not hatred. Having been born in Belgium he didn't start from a belief in the inferiority of other countries, but he loved Britain for the security it offered his family and the gentle decency of our nation.

"When we went on holiday abroad, the part he would look forward to the most was coming home. When he taught in America, he hated being away from our family and from Britain.

"When he thought of how many Jews had been killed, including members of our family, he felt very lucky that his boat from Belgium had come here."

In its examination of Ralph Miliband, the Daily Mail article stated: "As for the country that gave him and his family protection, the 17-year-old wrote in his diary: 'The Englishman is a rabid nationalist. They are perhaps the most nationalist people in the world . . . you sometimes want them almost to lose (the war) to show them how things are. They have the greatest contempt for the Continent . . . To lose their empire would be the worst possible humiliation'.

"This adolescent distaste for the British character certainly didn't stop him availing himself of the fine education that was on offer in this country, or spending the rest of his life here."

The article also quotes a letter attacking the British establishment. It adds: "Given this tirade, one is entitled to wonder whether Ralph Miliband's Marxism was actually fuelled by a giant-sized social chip on his shoulder as he lived in his adoptive country.

"He opposed the Falklands War with such a ferocity that he even swore - a rare occurrence - at the sight of Margaret Thatcher's soaring popularity."