British bombing raids killed a thousand German civilians a day when World War II was already won, says the historian sparking debate on whether Churchill was a war criminal.

German historian Jorg Friedrich argues the UK killed more than 635,000 civilians, including 75,000 children, during "indiscriminate" raids over five years.

It is tragic that so many civilians died, but let's ask ourselves who started the war

Winston Churchill Ex-premier's grandson

Mr Friedrich says he has never accused Churchill of being a "war criminal" - that is just the way British newspapers have interpreted his claims.

The grandson of the wartime prime minister Sir Winston Churchill, former MP Winston Churchill has countered the claims, saying the bombing raids were successful in disrupting German arms manufacture.

'Indiscriminate'

The controversy has erupted with the serialisation in German newspapers of Mr Friedrich's book, The Fire: Germany Under Bombardment 1940-45.

The historian told BBC Radio 4's Today programme: "It has been said by British historians for years that there was an indiscriminate bombing of civilian areas in the German cities during five years.

"There is nothing new about that."

Dresden was the most famous Allied bombing

Whether or not the bombing campaign was a war crime was debatable, he said.

"It made no military sense - the peak of the bombing campaign was between January 1945 and April 1945 when the war was effectively won," said Mr Friedrich.

The daily death toll of 1,023 was twice as many each day as were killed in the German bombing of Coventry, he said.

Targeting factories

The former UK premier's grandson denied the suggestion that the bombings were unnecessary.

"The conflict was not over, the conflict was reaching its climax," Mr Churchill told Today.

"It is tragic that so many civilians died, but let's ask ourselves who started the war, who invaded Czechoslovakia, Poland, Belgium, Holland, France, who launched the terror bombings of civilians."

Often the civilians killed were working in munitions factories which were sustaining German's war making capacity, argued Mr Churchill.

Irrespective of the row, Sir Winston Churchill lies third in the BBC's Great Britons vote, behind Brunel and Diana, Princess of Wales.

His case for the Great Briton crown will be taken up on BBC Two on Friday by former Labour cabinet minister Mo Mowlam.