The Conservatives' internal inquiry into MP Aidan Burley said that despite accepting that he left the dinner in protest at one guest raising a Nazi-themed toast, he failed to make it "explicitly clear" that he objected.
"Given the standards expected of a Member of Parliament, he should have done so."
After the incident was made public in 2011, the Conservative MP Aidan Burley wrote a letter to the Jewish Chronicle in which he claimed he "wished I left as soon as I had realised what was happening."
On reflection, I wish I had left as soon as I had realised what was happening. What was happening was wrong and I should have completely dissociated myself from it.
I had a choice, and I made the wrong choice NOT to leave.
I apologise for this error of judgment.
More top news
The so-called mini-Beast from the East has swept in, bringing with it snow, ice and strong winds.
London arts and textiles teacher Andria Zafirakou beat 30,000 others from 170 countries to be crowned winner at the ceremony in Dubai.
The family of a mother and daughter who died in a shooting in St Leonards, Sussex, have described them as "beautiful people".