Fine Gael TD Paschal Donohue has questioned whether Libertas founder Declan Ganley may have an ulterior motive for advocating a No vote in the forthcoming EU Fiscal Treaty Referendum.
It has emerged that Mr Ganley is chairman and chief executive of an asset management agency based in Switzerland, called St Columbanus AG.
Deputy Donohue said that this company profits from economic uncertainty, something which he says is highly likely if Ireland rejects this treaty.
"So you have a stake in a company that's asking people to put money into Swiss accounts, move out of the euro, to profit from economic uncertainty, that's the company you're involved in, and at the same time what you're doing is calling for a No vote within Ireland, which would accelerate that uncertainty, within Ireland and within the eurozone," said Deputy Donohue.
Howeever, Mr Ganley has denied that there is any conflict of interest between this business venture and his campaigning for a NO vote.
"You are questioning my integrity," he responded.
"St Columbanus AG does not target clients outside of Switzerland - it is regulated in Switzerland and is just in Switzerland."