Ministers Paschal Donohoe and Charlie Flanagan have declared their backing for Leo Varadkar in the Fine Gael leadership race.
Mr Donohoe stated his intention to vote for Minister for Social Protection Mr Varadkar in an interview on RTÉ’s Morning Ireland.
Minister Donohoe described Mr Varadkar as "the most capable politician of my generation", adding he "has all the qualities needed to lead Ireland as we face into a future of great opportunities and new risks".
He described Simon Coveney as "a very fine politician" but said he believes Mr Varadkar has the "rare combination of intellect and judgement needed for leadership".
Mr Donohoe listed Minister Varadkar's achievements, including the decision to go ahead with the Luas cross-city line, the Gathering, implementing the under-sixes and over-70s GP cards, and making the final decision on the National Children's Hospital, as well as extending maternity benefits and recognising the needs of the self-employed.
He said that Minister Varadkar has a "vision of a resilient and competitive economy" that can support a fairer Ireland.
Mr Donohoe said it is a matter for the next taoiseach whether he would have a Cabinet role, refusing to say whether he would seek the role of Minister for Finance.
Minister for Foreign Affairs Charlie Flanagan, meanwhile, declared his intention to support Mr Varadkar saying he was the "change candidate".
Speaking on RTÉ's Today's with Seán O'Rourke programme he said a leadership election is time for renewal and Mr Varadkar reflects a changing Ireland, a diverse Ireland and will broaden Fine Gael's support base.
He said that after ten years of crisis management, it's time for a new direction for Fine Gael and the country and Mr Varadkar is the person to set a new ambitious course for Ireland.
Minister of State Paul Kehoe has also confirmed his support for Mr Varadkar.
In a statement, Mr Kehoe said Mr Varadkar's "capacity to build a strong support base is testament to his willingness to work with party colleagues."
As the leadership contest enters its second day more members of the parliamentary party, including a number of other senior ministers, are due to indicate who they are supporting in the contest.
Based on early declarations, Mr Varadkar has established a lead within the parliamentary party but those campaigning for Minister for Housing Simon Coveney say a significant number remain undecided.
Mr Varadkar has already secured the public endorsements of around 30 members of the parliamentary party.
This is important as the 73 TDs, senators and MEPs who are members of the parliamentary party have a 65% share of the overall vote with party members having 25% and councillors 10%.
Those working on Mr Varadkar's campaign say they expect at least five ministers to come out in support of him today.
However, those campaigning for Mr Coveney, who has around 20 supporters so far in the parliamentary party, believe another 20 are undecided.
Separately, the Fine Gael National Executive met last night to finalise the details of the contest with four regional debates now confirmed in Dublin, Carlow, Ballinasloe, and Cork from the end of next week.
The debates will be followed by four days of polling in 26 locations nationwide with the new leader confirmed on 2 June.
However, the next few days will be very telling in terms of the outcome.
Mr Coveney set out his stall for the leadership during his first interview of the campaign on RTÉ's Prime Time last night.
He said one of the jobs that the new taoiseach and the new leader of Fine Gael is going to have to do is keep the Government together and he said he is well placed to do that, having been involved in putting the 'confidence and supply' agreement in place.
He advised people not to confuse someone who is good at putting deals together with someone who is weak.
Taoiseach Enda Kenny is in London today for a number of enagagements including a speech to the Ireland Funds Great Britain group.
The address will take place at lunchtime in the city centre where the Taoiseach will also meet members of the Global Irish Network and clients of Enterprise Ireland.
Mr Kenny will visit the Irish Cultural Centre in Hammersmith, which has been extensively redeveloped in recent years and is due to officially re-open in the coming weeks.