The veteran Labour MP, who is Jewish and lost relatives in the Holocaust, said being investigated by the party after a row with Mr Corbyn had made her feel like "a Jew in Germany in the 30s".
She accused her party leader of being on "the wrong side" of the line between being pro-Palestinian and antisemitic and suggested "the cult of Corbynism" had allowed this to happen.
The MP was told she faced disciplinary proceedings last month after an furious confrontation over antisemitism in Labour in which she accused Mr Corbyn of being a "racist and antisemite". The investigation was later dropped after she threatened to take the party to court.
Labour hit back as the latest row over antisemitism escalated, saying Dame Margaret's comments were "extreme and disconnected from reality".
Speaking to Sky News, Dame Margaret compared her treatment by Labour to the actions of the Nazis, suggesting she felt she had been punished for being Jewish.
She said: "On the day that I heard they were going to discipline me and possibly suspend me, I kept thinking: what did it feel like to be a Jew in Germany in the 30s? It felt almost as if they were coming for me."
The MP said her father, who fled Nazi Germany, had told her as a child that "you've got to keep a packed suitcase at the door, Margaret, in case you ever have to leave in a hurry".
Speaking of finding out that Labour had opened a probe into her conduct, she said: "When I heard about the disciplinary [action] my emotional response resonated with that feeling of fear that clearly was at the heart of what my father felt when he came to Britain."
She compared her treatment to "McCarthyism" and suggested it was part of a "purge" of opponents of Mr Corbyn.
Asked about her party leader, Dame Margaret said: "It's a very fine line between being pro-Palestinian and the Palestinian cause, which he's always believed in, and being antisemitic, and I think he's gone the wrong side of that line.
"I think it's a bit scary we've got this growth of populism - whether its Trump, whether its Boris Johnson and now whether it's the cult of Corbynism - which allows these sort of attitudes to emerge, and that's what scares me."
In response, a Labour spokesperson said: "Jeremy is determined to tackle antisemitism in the Labour Party, so Jewish people feel it is a warm and welcoming home.
"The comparison of the Labour Party's disciplinary process with Nazi Germany is so extreme and disconnected from reality, it diminishes the seriousness of the issue of antisemitism.
"We all need to work together to build support and confidence in the Labour Party among Jewish communities in Britain."
Dame Margaret said she had received "thousands" of supportive emails and letters from people who she described as being part of "Middle England", including many non-Jews.
She called on Mr Corbyn to accept an internationally-recognised definition of antisemitism that has been the subject of a major row in Labour in recent weeks, but said this would "only be the start of a very, very, very long journey in rebuilding trust with the Jewish community".
She added: "As leader of the party he has got to start healing that rift. That's his job, that his responsibility, that what he's leader of the Labour Party for."
The MP also criticised Len McCluskey, general secretary of the Unite trade union and a close ally of Mr Corbyn, after he condemned Jewish leadership groups and suggested the row over antisemitism was being exploited to undermine the Labour leadership.
Dame Margaret said: "I find that offensive I think that's trivialising the issue of antisemitism to pretend that somehow we're using that for cheap party political purposes. I'm not, and I think most of those colleagues who are with me, Jews and non-Jewish MPs feel exactly the same as I do."
Join our commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies