The Spanish cabinet is to discuss the next steps in the process of King Juan Carlos's abdication and the accession of his son, Crown Prince Felipe.
The king announced on Monday his intention to abdicate after nearly 40 years on the throne.
Ministers will discuss the steps needed to approve Crown Prince Felipe's accession to the throne.
Juan Carlos was seen as popular for much of his reign, but recently many Spaniards have lost confidence in him.
Prime Minister Mariano Rajoy said the cabinet meeting would aim at carrying out the "constitutional measures" needed to clear the way for the succession.
The Spanish constitution does not have a precise law regulating abdication and royal succession, and ministers will discuss the special legislation that will be necessary for the process.
Prince Felipe will become King Felipe VI and will inherit an institution whose reputation has been tarnished by scandals in recent years.
King Juan Carlos announced his decision on Monday in a televised address.
"A new generation must be at the forefront... younger people with new energies," the 76-year-old king said.
Prince Felipe will have to contend with the damage done to the standing of the monarchy by a long-running corruption investigation into the business dealings of his sister and her husband.
Support fell further when it was discovered King Juan Carlos had been on a lavish elephant hunting trip to Botswana in April 2012, in the middle of Spain's financial crisis.
On Monday evening, thousands of protesters took to the squares of several Spanish towns and cities demanding a referendum on whether the monarchy should continue.
Juan Carlos took the throne in 1975, after the death of General Francisco Franco, the military dictator who had ruled for 36 years.
The king became Spain's first crowned head of state for 44 years.
But he soon ignored Franco's supporters, who wanted an extension to autocratic rule, and ushered in a new system of parliamentary monarchy.
In later years he became more of a figurehead.
He has been credited as a stabilising force for independence-minded areas such as Catalonia and the Basque region.
Prince Felipe and his wife - former television presenter Princess Letizia - have recently taken on more important roles in ceremonial events.
Felipe appears to have been untarnished by the scandal.
But the BBC's Ignacio del los Reyes, in Spain, says there is still concern over whether the couple will be able to save a damaged institution.
RECENT EUROPEAN ABDICATIONS
June 2014: King Juan Carlos of Spain steps down, saying he is passing the role to a younger, energised generation.
July 2013: Belgian King Albert II abdicates in favour of his son, Philippe, for health reasons.
April 2013: Queen Beatrix of the Netherlands hands the throne to her son Prince Willem-Alexander, saying he is ready to reign and it is time for the throne to be held by "a new generation".