The Spanish Congress of Deputies convenes on 17 August for the first time since the July election. Eventually an investiture vote will take place for a new PM. However, the unsettled political landscape following the inconclusive election could result in a constitutional crisis, with King Felipe VI placed in the position of potentially making a partisan decision.

• Under the Spanish constitution, the monarch must put forwards a PM candidate for the first investiture vote. Usually this is fairly clear, with the leader of the majority party/coalition named. However, with both the main blocs short of a majority the decision is not clear.
• Centre-right Popular Party (PP) head Alberto Nunez Feijoo leads the largest party in parliament, but looks set to fall short of a majority coalition. Acting PM Pedro Sanchez from the centre-left PSOE looks in a better position to put together the requisite support, but that is not yet certain.
• In 2016, then-PM Mariano Rajoy turned down the prospect of an investiture vote despite being head of the largest party as it became clear he would not win. This was to ensure that the King was not brought into any partisan struggle. However, this time around both the PP and PSOE are seen to be keen as having their candidate voted on first.
• If no agreement can be reached by both sides, the King could be put in the position of choosing between them, risking the anger of supporters of the party not selected for the first vote.