Michael Martin had backed the Laois/Offaly TD Yesterday Afternoon.
The Taoseach's set to appoint a new Agriculture Minister today, after Barry Cowen was sacked last night.
It followed Mr Cowen's refusal to provide further public statements on allegations he attempted to avoid a garda checkpoint in 2016.
He admitted he was caught drink driving, but strongly denies trying to evade gardaí.
In a statement, the Offaly TD says the decision to sack him was surprising and disappointing.
Sinn Féin's Health spokesman David Cullinane says the Taoiseach needs to fully explain why his position flipped yesterday:
TII Pressured To Provide Update On Major Midlands Road Project
Edenderry Festival Lineup Revealed
Midlands-Based Student Takes Bronze At Culinary Contest
New Legislation Just The First Step -Midlands Cancer Support Centre
Irish Credit Unions Hit Record Lending Levels
ADHD Ireland Issues Social Media Warning
Laois Footballer Tackles First Dates Ireland
New Jobs Announced For Midlands
Cancer Survivors Welcome ‘Right to Be Forgotten’ Mortgage Reform
Irish Cancer Society Calls For Support This Daffodil Day
Interactive Offaly Event Highlights Barriers Faced By Abuse Survivors
Lawyers Seek To Overturn Murder Conviction Over Midlands Shooting
Burglary Gang Breaks Into Midlands Shopping Centre
Laois TD Wants New Fire Station Fastracked
Midlands Housing Commencements Continue To Rise
Almost 39,000 Midlands Workers Auto-Enrolled In New Government Pension Scheme
RTB Figures Show Annual Increase Of Over 10% For New Tenancy Rates In Offaly
12 One Act Plays To Be Staged By Laois Arts Collective
No Indication Of Meningitis Outbreak In Ireland - HSE
Laois Library To Host 'Skills For Life' Event