George Galloway has been suspended from the House of Commons for bringing it into disrepute.
MPs still have to approve the suspension but the Commons committee on standards and privileges recommended he be suspended for 18 days.
Mr Galloway, a Respect MP for Bethnal Green and Bow, rejected the committee's finding and said he was being punished for the robust way in which he has defended himself.
The committee found Mr Galloway failed to register his interest in the Mariam Appeal or the individual donations it received. He also did not declare his interest in the appeal on all occasions he should have done.
Moreover, it found the MP was excessive in his use of parliamentary resources to further the Mariam Appeal, which was founded by Mr Galloway to provide medical treatment for Iraqis in Saddam Hussein's Iraq.
The committee acknowledged that it can be difficult to distinguish between parliamentary duties and external campaigns, but Mr Galloway's use of his Westminster office for the Mariam Appeal was excessive.
However, the Respect MP was again exonerated of receiving any money from Saddam Hussein under the UN oil-for-food scheme.
The committee concluded that "Mr Galloway has acted in several ways in a manner likely to bring the House into disrepute".
It ruled an apology to the House would be insufficient and he should be suspended for 18 sitting days.
Mr Galloway argued his suspension was a vindictive punishment for his questioning of the committee's impartiality.
The MP said: "After a four-year inquiry - costing a fortune in public funds - the report asks me to apologise for not registering consistently the Mariam Appeal I established (the commissioner concedes that I did so, but randomly) and for using House of Commons resources allocated to me to campaign against the policies of those now sitting in judgment on me.
"The committee of MPs acknowledges that "had these been the only matters before us, we would have confined ourselves to seeking an apology to the house.
"However, in a surprisingly thin-skinned rejoinder, the MPs complain that because I questioned their impartiality and made trenchant criticisms of evidence and witnesses (which, incidentally, they don't attempt to refute in most cases) I am to be suspended for 18 days."
Mr Galloway stressed he had been cleared of taking money or benefiting from the former Iraqi regime.
The MP has already been criticised by the Charity Commission for failing to ensure funding for the Mariam Appeal had not been diverted from the oil-for-food programme.