King Felipe made the decision after meeting earlier in the day with both Nuñez Feijoo and acting Prime Minister Pedro Sanchez, who is also the Socialist Party (PSOE) leader. This is the second day of consultations between the King and main party leaders after the general election on July 23 failed to produce a candidate to form a new government.
The Spanish Constitution merely states that the Monarch has to name a candidate to try and win an investiture vote in Congress, but it does not specify whether this should be the leader of the party that has won the most votes, or the party leader who can gather the most parliamentary support.
"I will get in contact with the candidate to be Prime Minister to learn their opinion over the best opportunity to carry out the investiture debate and take a decision," Congress Speaker Francina Armengol said in the evening.
In the wake of the King's decision, Nuñez Feijoo posted on social media: "I am grateful to His Majesty the King for his decision to name me as candidate to be Prime Minister. We will give a voice to the over 11 million citizens who want change, stability and moderation with a government that defends the equality of all Spaniards."
Earlier in the day, both Sanchez and Nuñez Feijoo said they were willing to try and form a government, with Sanchez highlighting the progressive majority that saw Armengol elected as the Congress speaker last week.
"There is no alternative other than to reform a progressive government to consolidate the advances of the previous years. Those who questioned the previous government have not received either the votes or the seats to carry out their proposals," said Sanchez. However, he added that he would respect any decision made by the King.
Meanwhile, Feijoo said he had the support of Vox, Coalicion Canaria and the UPN from Navarre. The PP leader will have two chances to become prime minister when the investiture vote is held. In the first vote he needs to win an overall majority of 176 seats in Congress. Otherwise, a simple majority would suffice in a second vote 48 hours later.
If he loses both votes, Sanchez would then have the chance to form a government, but if nobody is able to win the necessary support within two months, Congress would be dissolved and a new general election called 47 days later.