With the dust still settling on the 23 July general election, much focus has been paid to the parliamentary arithmetic in the lower house of the Cortes Generales - the Congress of Deputies - and the ability or lack thereof of either incumbent PM Pedro Sanchez or opposition leader Alberto Nunez Feijoo to put together enough support to win an investiture vote. In the Senate, though, Feijoo's centre-right Popular Party (PP) has secured an absolute majority, with 120 of the 208 seats.

• With the PP lacking the requisite support from smaller parties, the only feasible option to avoid snap elections is for centre-left PSOE head Sanchez to gain the backing of nearly all regionalist parties in an investiture vote.
• In order to gain the support of the populist pro-Catalan independence 'Together for Catalonia' (Junts) and its seven deputies, Sanchez is likely to have to make some form of concession regarding further devolution or even a path towards a legal independence referendum.
• In Spain's asymmetric bicameral system, the Congress usually has the power to override Senate amendments or vetoes with a majority vote. However, so-called 'organic laws', involving civil rights or regional devolution, require absolute majorities in both chambers to pass.
• As such, the PP could seek to block any legislation regarding handing further powers to the Catalan Gov't (or indeed devolved administrations of other autonomous communities). This could raise the risk of the collapse of any nascent PSOE-led administration should one be formed.