Mairead McGuinness says the Standards in Public Office Commission should look into Michael D'Arcy's career move.
She was questioned about the controversy surrounding her party colleague, while being assessed for her suitability for the role of EU Commissioner for Financial Services.
Mairead McGuinness sat through a three hour grilling from MEPs hoping to get their seal of approval to become Eu Commissioner for Financial Services.
The reshuffle is a result of Phil Hogan's resignation following the golf-gate controversy.
A concern was raised about three Irish citizens holding senior financial roles in EU institutions. Finance Minister Pashcal Donohoe is President of the Eurogroup, while Philip Lane is the Chief Economist of the European Central Bank.
Following Michael D'Arcy's resignation as a senator to take up a role with Irish Association of Investment Managers, Mick Wallace asked does the issue of "revolving doors" need to be addressed.
The Midlands North West MEP faced further questions on her stance on taxation, how she would tackle money laundering and improve cross border lending.
The parliament will vote on whether to confirm her for the post on Wednesday.
