Lib Dem MP David Ward has had the party whip withdrawn for bringing the party "into disrepute" over language used about the Israel-Palestinian conflict.
In a letter to the MP for Bradford East, Lib Dem chief whip Alistair Carmichael said it was with "immense disappointment" the party leadership felt he had to be suspended from the party over a tweet.
On July 13 Ward tweeted: "Am I wrong or are am I right? At long last the #Zionists are losing the battle – how long can the #apartheid State of #Israel last?"
His suspension will only last until September 13. Given the Commons rises for recess on Friday the period he will not be a member of the Lib Dem parliamentary party when parliament is sitting is for two weeks at the start of September.
In his letter Carmichael said: "We were in unanimous agreement that questioning the continued existence of the State of Israel fails the test of language that is 'proportionate and precise'."
"We want to be clear with you that in this process we are not concerned about your views and opinions on the policies of present or previous Israeli governments, nor the situation in the Israeli-occupied territories, nor the strength of feeling with which your views are held.
"As we have sought to impress upon you repeatedly, we are having to decide on whether language you chose to use in January and February, and now this month, is language which brings the party into disrepute or harms the interests of the Party."
Earlier this year Ward was summoned to a meeting with Carmichael after he made reference to "the Jews". The row blew up over a posting made by Ward on his website after signing a memorial book to mark Holocaust Memorial Day.
He said: "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 his letter to Ward today, Carmichael added: "It is also immensely frustrating for us to find ourselves constantly responding to questions about disproportionate and imprecise language from you. These interventions cause considerable offence rather than addressing questions of political substance about the plight of the Palestinian people and the right of Israel’s citizens to live a life free of violence.
"It is extraordinarily difficult to gain traction in that debate at an effective political level if the expression of our concerns is undermined by the way your language misrepresents the view of our party."