The deadline is next Monday, but today most politicians and sources on all sides cast doubts on the possibility of breaking the deadlock which has paralysed the Spanish state for the past five months.
If Socialist Party leader, Pedro Sanchez, fails to "square the circle", Spain will hold its fourth election in four years.
Pedro Sanchez and its party were the biggest party in April’s election but failed to secure a parliamentary majority.
Chances of a new government are very slim.
If there is no breakthrough, a new election will be held on 10 November.
Pablo Iglesias, leader of the left coalition Unidas Podemos, said after meeting the king that he would support Sanchez’s confirmation only if he agrees to a coalition government.
The Socialists, however, have ruled out a coalition government with Podemos.
Indeed Pablo Iglesias had met with Sanchez before meeting the king. "I haven't seen - said Iglesias in a press conference - any will in Sanchez as to make us think he would offer a last minute deal. Clearly you never know, but to be honest it looks difficult for the situation to unlock."
