Fine Gael Parliamentary Party Chairman Martin Heydon has written to the General Secretary of the party about an alleged bullying issue.
Senator Catherine Noone raised concerns about bullying and sexism from a male colleague at a parliamentary party meeting last night.
The senator told the meeting that a male colleague regularly talks down to her and is misogynistic.
This evening, Parliamentary Party Chairman Martin Heydon has written to General Secretary Tom Curran about the issue.
A spokesperson for Fine Gael said due process will be followed and the matter will be dealt with swiftly.
They say they expect party colleagues to treat all with the utmost respect, professionalism and dignity at all times.
Senator Noone told her colleagues last night the issue had become too much to take.
The Taoiseach Leo Varadkar is understood to have responded strongly to the issue saying it would not be tolerated.