Fine Gael Ministers are said to be actively encouraging members to support Fianna Fáil TD Seán Ó Fearghaíl for the position of ceann comhairle.
It is understood two senior figures were urging TDs to back Mr Ó Fearghaíl for the role despite two TDs from their own party also contesting.
Andrew Doyle and Bernard Durkan are said to be extremely disappointed and angry at the move, which is said to be a tactical decision by Fine Gael.
“There is an encouragement from within to support Ó Fearghaíl,” a party source said.
"It makes more sense for us to have one less Fianna Fáil TD and not lose another Fine Gael TD. They don't want us to support Maureen O'Sullivan because that would make Dublin Central a two-seater, and would make it even harder for Paschal Donohoe to be re-elected."
Mr Ó Fearghaíl is said to be the favourite for the position which will be decided by secret ballot today. He has written to and contacted every Fine Gael TD to seek support for the position.
Mr Durkan and Mr Doyle spoke at their parliamentary party meeting last night seeking support for the role.
One Fine Gael TD said it was a “scandal” that the party was actively not supporting its own candidate. “There will be very close scrutiny of the votes when they emerge.”
Sinn Féin met yesterday to decide who to transfer to after supporting their own candidate Caoimhghín Ó Caoláin. There was no direction given to members, but it is expected the members will support Ms O’Sullivan.
Five TDs have sought the position which has been occupied by Fine Gael TD Seán Barrett since 2011.
Mr Doyle, Mr Durkan, Mr Ó Caoláin, Mr Ó Fearghaíl and Ms O’Sullivan are the candidates.