It will become clear later the main differences between the two contenders for the leadership of Fine Gael.
He will face housing minister Simon Coveney after nominations closed for the leadership of the governing centre-right Fine Gael party.
Mr Varadkar may seem an unlikely frontrunner in socially conservative Ireland.
The Social Protection Minister will follow that up by conducting formalities at the opening of Longford-Westmeath TD Peter Burke's constituency in Mullingar on Monday evening.
Simon Coveney at his leadership campaign kick off rally in Cork's Capitol building tonight (Saturday) where over 400 party members, senators and TDs turned out to support the Fine Gael leadership candidate. "It's started really well and I'm really humbled at the level of support I have received from my colleagues, [but] I'm not counting my chickens".
'Mr Kenny has done the party and the country an enormous service, especially in the last six years when he oversaw the rescuing of our country from the brink of collapse, ' said Deputy Daly.
Mr Coveney was asked by reporters if he knew which way Mr Breen and Mr Carey would vote and his response was awkward.
"I'll be having conversations with Pat and Joe just like I've had with all of the other members of the parliamentary party and they'll make their choices and I'll respect those choices", Mr Coveney said.
"We can repeat the mistakes of the past, allow ourselves to lose control of public spending, fuel the property market ... or this time we can get it right". "I'm not going to be putting people under pressure in the spotlight of the media".
Mr Coveney promised to consider how post-Brexit Ireland should maintain its competitiveness in key areas like taxation and infrastructure, including appointing a minister for infrastructure.
"We have a contest under way", he said.
There is two weeks to go in the battle to become Ireland's next Taoiseach.
It remains to be seen how Tanaiste Frances Fitzgerald will vote, but sources say she will endorse her Dublin colleague.
Strategists close to Mr Coveney are reported to have described a win as "technically difficult" but have refused to concede defeat.