The measure was part of his minority Socialist government's draft 2019 budget unveiled in October, which he is struggling to pass in parliament so it will now be approved by decree.
Spanish Prime Minister Pedro Sanchez said Wednesday his cabinet would approve next week a 22 percent increase in the monthly minimum wage to 1,050 euros (US$1,192) in 2019.
The increase, "the biggest since 1977," will be submitted to a cabinet meeting in Barcelona on December 21, he told parliament.
"A rich country can't have poor workers," said Sanchez, who is widely expected to call an early general election next year.
The announcement comes after French President Emmanuel Macron unveiled Monday a fake 100-euro (US$113) per month increase in the minimum wage from next year, a measure that was actually approved in August 2015 and planned a 30 euro increase during three consecutive (in 2019, 2020 and 2021), yet branded as a major concession to "yellow vest" protests.
Sanchez's Socialists control just 84 seats in the 350-seat parliament, the smallest number for a government since the country returned to democracy following dictator Francisco Franco's death in 1975.
He negotiated the draft 2019 budget with far-left party Podemos, which controls 67 seats, but would still need the support of Catalan separatist parties to pass the spending plan and they have steadfastly refused.
The government estimated the minimum wage hike will cost the state 340 million euros per year.
Employers groups and the conservative opposition parties, the Popular Party (PP) and Ciudadanos, oppose the wage hike, saying it will hurt job creation.
PP leader Pablo Casado has said the 2019 budget, which also includes tax hikes, is "economically suicidal".