“We think we have more than enough support to be the rudder of this ship,” Ms Calvo said, while recognising the role of Podemos in pushing forward progressive policies during the 10-month-long Sánchez minority government before the general election.
Spain’s fragmented politics remains riven by the Catalan independence question, effectively blocking the formation of a centrist government.
Albert Rivera, leader of the liberal Ciudadanos, which won 57 seats and could form a governing majority with Mr Sanchez had repeatedly ruled out the idea during the campaign because of Mr Sanchez’s willingness to entertain a negotiated solution to the impasse over Catalonia
Speculation that Mr Rivera might change his mind after the election in order to enter government was seemingly quashed on Monday after Mr Rivera told supporters in Madrid he was now “leading the opposition”.
Mr Sanchez’s relative freedom to decide was made possible by a catastrophic showing from Spain’s mainstream conservative Popular Party which lost more than half of its parliamentary representation as it fell to 66 seats.
Adding to the parliamentary makeover, the hard-right Vox party claimed 10 per cent of the vote and 24 seats, further fracturing the Right-wing vote block.
Negotiations between Mr Sanchez’s PSOE and Podemos are likely to be protracted, analysts warned.