Senior Liberal Democrats are considering removing the whip from MP David Ward in the wake of his repeated slurs against Jews and Israel.
The Bradford East MP is to meet Nick Clegg and deputy party leader Simon Hughes at the start of next week, where he will face further questions over statements such as that "the Jews" have failed to learn the lessons of the Holocaust or that there is a powerful pro-Israel "machine" in operation.
He had already been formally censured and had committed not to "again use the phrase 'the Jews' in this context", when, last week, he suggested that in discussing it might be advisable to substitute "the Jewish community" for "the Jews".
Speaking to representatives of Anglo-Jewry, Chief Whip Alistair Carmichael pledged this comment would be treated as a fresh issue.
Mr Carmichael has now confirmed that the party is willing to invoke "the full range of sanctions" over Mr Ward's conduct and that they will meet the MP again once Mr Clegg returns from a trip to Mozambique on Saturday.
The MP, who has been backed by anti-Israel academic Noam Chomsky, was summoned to Mr Carmichael's office on Monday and given a chance to explain himself.
But he clarified that his statements had not been misreported and there was "no innocent explanation" and refused to backtrack.
Mr Carmichael said he was following the parliamentary party's disciplinary process for breaches of party discipline. "Obviously without prejudging the outcome all options are available at the end of that process," he said. "I can confirm that these options include the suspension or withdrawal of the whip."
He said Mr Ward's was the most serious disciplinary issue he had encountered since becoming whip in 2010. "In the time I've done this job it is the first time I've even got to the point of issuing a formal letter of reprimand, and the first time we've gone beyond that." Questioned on "MPs who use the conflict in Israel to make inflammatory comments about Jews" in parliament, Mr Clegg said he was "unambiguous in my condemnation of anyone… who uses insensitive, intemperate, provocative and offensive language to describe a long running conflict about which people have very strong feelings".