Sánchez’s high-stakes gamble, which he announced just hours after the results came in, is based on the hope that any such deals will help to galvanise and mobilise leftwing voters and prove distasteful to supporters on the PP’s moderate wing.

Speaking at the Moncloa palace in Madrid on Monday morning, Sánchez said he had informed King Felipe of his decision to dissolve parliament and call a general election on 23 July, five months before the poll had been scheduled to be held.