Former Act Party leader Rodney Hide is calling for convicted Lombard director Sir Douglas Graham to be stripped of his knighthood.
Graham, along with three other company directors, was found guilty of making false statements in the lead up to the collapse of the failed finance company in 2008.
Yesterday he was sentenced to 300 hours community service and ordered to pay $100,000 in reparations.
Hide said Prime Minister John Key should strip Graham of his knighthood following the conviction if the former cabinet minister is not willing to relinquish it.
Hide told Close Up tonight the integrity of the royal honours system is in jeopardy if convicted criminals are allowed to retain an honour designed to recognise distinguished members of society.
"The fact is I don't think we should be obligated to call someone Sir who is a convicted criminal.
"I think he should make it easy for the Prime Minister and say 'please take it off me'," said Hide.
Wellington lawyer and former Act Party MP Stephen Franks said there was no law governing removing someone from the Order of Merit but rather it was a matter of honour and integrity.
Franks said a knighthood should only be withdrawn when the recipient's integrity was in question, which was not the case for Graham.
He said the Wellington High Court judge found Graham had not deceived Lombard investors.
"This was a an offence of carelessness. This was like a speeding ticket," said Franks.
"I think the law is demeaning itself by attributing a criminal label to stuff that should have a different charge."
New Zealand's most recent member of the Queen's order of merit to lose his title was former Christchurch Deputy Mayor Morgan Fahey.
He was stripped of his OBE in 2000 after he was convicted and jailed for rape, sexual violation and indecent assault.
However, OBE recipient author Margaret Mahy retained her honour despite a drink driving conviction in 2008.