Green Party Leader Mr Trevor Sargent has called for the removal of the Environmental Protection Agency director over her previous role as a senior employee of waste-disposal company Indaver Ireland.
Ms Laura Burke was formerly project manager for Indaver Ireland's planned incinerators at Ringaskiddy, Co Cork, and Carranstown, Co Meath.
She will be asked to absent herself from an EPA board meeting next month that will consider whether or not to approve the controversial Ringaskiddy incinerator.
"Ms Burke's position is no longer tenable," said Mr Sargent. "The fact that Ms Burke will not be allowed to attend the EPA board meeting, which will decide on the Ringaskiddy incinerator, only highlights the ongoing conflict of interest created by her appointment to the EPA.
"For the sake of the EPA's independence and strength it is important that there is no question mark over the motivation of its directors," he said.
"Ms Burke clearly should not have been appointed and should not continue. Apart from her lack of credibility in environmental protection arising from her previous role as a promoter of incineration, she effectively denies a more suitable expert a place on the EPA board. As a result, we now have a weaker EPA and a more vulnerable environment.
"Minister Cullen has made a series of appointments to the executive board of the EPA which show all too clearly that he sees the agency as protecting the interests of business, with environmental protection being given a very low priority."