Diane Abbott has been suspended as a Labour MP pending an investigation into a letter she wrote about racism for the Observer, the party has said.
The politician said "many types of white people with points of difference" can experience prejudice, in a letter published on Sunday.
But they are not subject to racism "all their lives", she said.
She later tweeted to say she was withdrawing her remarks and apologised "for any anguish caused".
Labour said the comments were "deeply offensive and wrong".
The BBC has approached Ms Abbott for comment.
In the letter, she wrote: "In pre-civil rights America, Irish people, Jewish people and Travellers were not required to sit at the back of the bus.
"In apartheid South Africa, these groups were allowed to vote.
"And at the height of slavery, there were no white-seeming people manacled on the slave ships."
She had been responding to an article in the Guardian questioning the view that racism "only affects people of colour".
Ms Abbott's letter prompted a backlash, including from the Board of Deputies of British Jews, which described it as "disgraceful" and her apology "entirely unconvincing".
The group had urged Labour leader Sir Keir Starmer to remove the whip.
In her apology, the MP for Hackney North and Stoke Newington said "errors" arose in an initial draft that was sent.
She continued: "But there is no excuse, and I wish to apologise for any anguish caused.
"Racism takes many forms, and it is completely undeniable that Jewish people have suffered its monstrous effects, as have Irish people, Travellers and many others."
Suspending the whip means Ms Abbott will not be allowed to represent Labour in the House of Commons, where she will now sit as an independent MP.
A Labour Party spokesman said: "The Labour Party completely condemns these comments, which are deeply offensive and wrong.
"The chief whip has suspended the Labour whip from Diane Abbott pending an investigation."
