The Liberal Democrats have "condemned" their MP David Ward for his "use of language" in a statement about Israel's treatment of Palestinians, issued ahead of Holocaust Memorial Day.
He accused "the Jews" in Israel of "inflicting atrocities on Palestinians... on a daily basis".
Mr Ward has been summoned to a meeting with party whips next week.
But the MP told the BBC he had chosen his words carefully and did not regret the timing of the statement.
The MP said it was "regrettable" he had been reprimanded by Liberal Democrat officials.
This Sunday - Holocaust Memorial Day - marks the 68th anniversary of the liberation of Auschwitz concentration camp, where more than one million people - mostly Jews - died.
Mr Ward, who has represented Bradford East since 2010, described Auschwitz as "the Nazi concentration and extermination camp which is the site of the largest mass murder in history" on his website.
The web page indicated that the MP supported efforts "to combat prejudice and racism today" by the Holocaust Educational Trust and had honoured "those who were persecuted and killed during the Holocaust" by signing a "Book of Commitment".
But it also included a statement from Mr Ward: "Having visited Auschwitz twice - once with my family and once with local schools - I am saddened that the Jews, who suffered unbelievable levels of persecution during the Holocaust, could within a few years of liberation from the death camps be inflicting atrocities on Palestinians in the new State of Israel and continue to do so on a daily basis in the West Bank and Gaza."
Karen Pollock, chief executive of the Holocaust Educational Trust, said she was "deeply saddened" that the MP had "deliberately abused the memory of the Holocaust".
She added: "These comments are sickening and unacceptable and have no place in British politics."
A Lib Dem spokesman said: "This is a matter we take extremely seriously. The Liberal Democrats deeply regret and condemn the statement issued by David Ward and his use of language which is unacceptable."
Jon Benjamin, chief executive of the Board of Deputies of British Jews, said: "We are outraged and shocked at these offensive comments about Jewish victims of the Holocaust and the suggestion that Jews should have learned a lesson from the experience.
"For an MP to have made such comments on the eve of Holocaust Memorial Day is even more distasteful, and we welcome the fact that the Liberal Democrats have sought to disassociate the party from David Ward's comments."
But Mr Ward told the BBC: "I've spoken to the chief whip, and he's got his views. I don't feel bad about it in any way. They consider my comments regrettable; I consider their reprimand regrettable."
The Lib Dem MP said any further disciplinary would be "a sad reflection on the values we all hold so dearly, particularly on free speech".
He also said his comments had received an "overwhelmingly positive" response from the public, with 80 unsolicited supportive emails, and just two from detractors.
While it was essential to remember the Holocaust as "one of the most horrific examples of man's inhumanity to man", he said, "should we not also remember when there are examples of atrocities being committed in the present?"