Three of the country's four largest parties have met with the president as he attempts the difficult task of forming a government from the stalemate delivered by the March 4 general election.
Luigi Di Maio, head of the anti-establishment Five Star Movement (M5S), was the last leader to speak with Mr Mattarella after the centre-left Democratic Party (PD) and right-wing coalition partners - the League and Silvio Berlusconi's Forza Italia (FI) - all visited the presidential Quirinal Palace before lunchtime on Thursday.
Mr Di Maio sat down with the head of state at 2:30 pm local time.
The right, led by League leader Matteo Salvini, won 37 per cent of the vote while the M5S garnered the biggest share of any single party with just under 33 per cent.
Speaking after the meeting, Mr Salvini reiterated his post-election mantra of bringing a "solid" right-wing group, which is "more interested in political program than in ministerial positions", to lead a new government.
"Plenty have come here to say 'no', but we have said 'yes' to the president," Mr Salvini said to reporters.
That call to arms came following an invitation from Mr Di Maio for Mr Salvini to abandon Mr Berlusconi, who the 31-year-old has refused to even meet since the elections, and work with the M5S to "change Italy".
However, Mr Salvini told Italian media that he would not exclude returning to the polls if "everyone maintains their personal or party's way of thinking".
After the consultations Italy's president will take some time to decide who, if anyone, can command enough seats to form a government or whether a fresh round of consultations is necessary.
This week's impasse has come about because no group is anywhere near a parliamentary majority in either the Chamber of Deputies or the Senate.
The right needs 51 more seats in the 630-seat Chamber and 23 in the Senate - which holds 318 seats - in order to form a stable majority.
The M5S need to secure the support of 94 more lawmakers in the lower house and 51 in the upper house.
Interim PD leader Maurizio Martina confirmed on Thursday his party's refusal to work with either the right or the M5S despite having enough seats - 111 in the chamber and 52 in the Senate - to form a government with either side.
Another roadblock in the way of a new government is the mutual antipathy between Mr Berlusconi and the M5S.
After meeting with the president, Mr Berlusconi said that FI is "not ready to form a government in which the politics of envy, social hatred, pauperism and justicialism prevail", in a dig at Mr Di Maio's party.
The 81-year-old media magnate and ex-premier, who is barred from public office due to a tax fraud conviction, has been a target of barbs from both Mr Di Maio and the M5S's stand-up comedian founder Beppe Grillo.
Mr Berlusconi is firmly against the M5S's basic income policy, which would extend to nine million people and, according to national insurance agency INPS, would cost Italy between €35-38 billion.
Despite being partners with eurosceptic Salvini, Mr Berlusconi spoke of a commitment to Europe that stood in stark contrast to the anti-EU tub-thumping favoured by the League.
The League remains the only party openly hostile to the bloc after Mr Di Maio softened his stance on Europe before the election saying that the European Union was Italy's "natural home".
Mr Salvini might head the right-wing but without FI, his chances of leadership vanish.
Should he decide to listen to Mr Di Maio and break with Mr Berlusconi - something figures within the PD have suggested has already been agreed - his League party would be the junior partner in a Di Maio government.