Public Expenditure Minister Brendan Howlin says he is backing John McNulty - despite the recent 'cronyism' controversy.
"I will be supporting the Government candidate," he said.
"It is important, we have important legislation to get through the Seanad.
"The decision of the Taoiseach and the Tánaiste in 2011 to appoint a number of Senators who couldn't be certain of taking a party whip means that getting legislation through the Seanad is difficult enough."
Minister Howlin will brief his colleagues on plans to reform State board appointments today.
He says he wants to ensure future appointments are “transparent” and open to anyone who is interested.
Meanwhile, Labour's Mental Health Minister, Kathleen Lynch, has acknowledged that some party members don't support John McNulty.
"If I thought for one minute I thought I'd have any great influence on them, I would probably be telling them what to do - I'm not sure I have that kind of influence," she said.
"I believe the choices are clear: we have a Government candidate, a Sinn Féin candidate, or a Fianna Fáil-supported candidate. In those circumstances, I will be voting for the Government candidate."