Deputy Premier James Merlino has vowed he will not be intimidated by a legal threat from alleged Mafia boss Tony Madafferi.

Mr Merlino told State Parliament on Thursday he had received two letters from Mr Madafferi demanding an apology and the retraction of statements he made about a lobster dinner with the Opposition leader.

The Deputy Premier has repeatedly said Opposition Leader Matthew Guy has questions to answer about the dinner at the Lobster Cave in Beaumaris earlier this year.

"I have received two letters from the lawyers acting on behalf of Antonio Madafferi, demanding I immediately retract statements regarding the dealings between the leader of the opposition and Mr Madafferi, to apologise and to pay their lawyer's money," Mr Merlino said.