The Green Party TD Ciaran Cuffe has agreed to step aside as the party's Environment Spokesman.
The move comes following the controversy over Mr Cuffe's ownership of shares in a number of oil companies.
He will remain as the party's Justice and Law Reform spokesman.
Mr Cuffe, who represents Dún Laoghaire, announced his decision at a meeting of the Parliamentary Party in Leinster House this morning.
The Green TD inherited the shares from his mother three years ago.
The $1.3m share portfolio includes investments of almost $70,000 in six oil exploration companies.
Party leader Trevor Sargent, accepting Deputy Cuffe's offer to stand aside, said it was important to note that at all times Deputy Cuffe had been in full compliance with the law and all relevant regulations.
He described the incident as 'a lesson to all of us in the Green Party'.
Mr Sargent said procedures were now being reviewed to ensure that all public representatives and candidates can stand over any financial interests they may have, from the point of view of compatibility with the Party's founding principles and constitution.
He added that all members of the Parliamentary Party accepted Deputy Cuffe's explanation that the difficulties arose because he had inherited the shares from his late mother.