David Starkey has been branded "irresponsible" and "deeply offensive" after comparing the Scottish Nationalist Party to the Nazi Party.
The outspoken BBC historian, 70, courted controversy by saying the Scottish were treating the English in the way the Nazis treated Jews.
He also remarked that the flag of Scotland – the saltire – was a "twisted cross" akin to the swastika, and drew comparisons between the Scottish economy and that of Nazi Germany's.
"You have as a symbol the twisted cross: the saltire or the swastika," he said.
"You have a passionate belief in economic self-sufficiency: known by the Nazis as 'autarky' and the Scots as 'oil'.
"And also you have the propensity of your elderly and middle-aged male supporters to expose their knees," he said, passing comment on the traditional dress of Scotland and Germany.
He added SNP supporters were "incapable of recognising that this is national socialism" and that "nationalism is much more important than the socialism, as it was in Germany".
Starkey's comments were seized upon by SNP's MPs who said the presenter was a "serial utterer of bile and bilge".
Kirsten Oswald, East Renfrewshire MP, said: "David Starkey's comments are irresponsible; deeply offensive to the Jewish community, the half of the Scottish electorate who voted SNP last month, and 60% who currently intend to vote SNP next year; and have absolutely no basis in reality."
Speaking on the Andrew Marr show, John Nicholson, East Dunbartonshire MP, said Starkey had offended Christians, Jews and the Scottish with the comments.
"Does he just say the silliest thing that comes into his mind on any given day?" he said.
"He says the St Andrews Flag, the saltire flag, looks like a swastika. He seems not quite to understand the origins of it. He calls it the 'twisted cross' rather than the cross that St Andrew was crucified on, out of respect to the original cross.
"It's offensive to Christians, to Jews and obviously Scots."
The SNP crushed Conservative, Labour and Liberal Democrat candidates in May's general election, winning 56 out of a possible 59 seats north of the border on an anti-austerity manifesto.