Rajoy's conservative Popular Party won the most ballots in Sunday's vote but lost its absolute majority in the 350-seat lower house of parliament, taking just 123.
The opposition Socialists won 90 seats, followed by the far-left Podemos with 69 seats and the centre-right Ciudadanos with 40.
Rajoy in January will face a vote of confidence on whether he can stay on as leader of the government.
If he falls short a second vote will be held 48 hours later with a lower bar to success -- he would just need to get more votes for than against him that time around.
That means if Ciudadanos and the Socialists were to abstain from voting in the second vote Rajoy would be able to get re-elected.
Ciudadanos, which shares many of the Popular Party's economic policies, has said it will abstain.
But the leader of the Socialists, Pedro Sanchez, said today his party would not support any effort by Rajoy to stay in power.
Sanchez did not completely close the door on the Popular Party -- he did not say if the Socialists would support the party if Rajoy were to step down as leader.
The Socialist leader reiterated that the Popular Party should be the first to try to form a government since it won the most votes. But he said if the party failed, his formation would "explore all options for there to be a government of change".
That outcome would mirror events in neighbouring Portugal where the ruling conservatives won an October election but fell to a Socialist government backed by leftist parties just days later.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
