Overview
- El País published simulations on Wednesday showing that the left’s new nationwide joint Senate list, called Senado de Progreso, has reduced the probability of a PP+Vox Senate majority compared with no agreements.
- The model finds PP and Vox would hold a majority in about 85% of runs with no deals, that the left joint list cuts that to roughly 60%, and that Vox withdrawing in 13 or 19 provinces would raise the right‑bloc odds to about 75% or 90% respectively.
- Vox can still withdraw candidates until the formal registration deadline on Monday, October 26, and PP and Vox are negotiating tactical options but cannot register a formal coalition because the coalition window has closed.
- The Senate uses open lists and a majoritarian rule that typically gives the most‑voted party three of four seats in peninsular provinces, so moves in a handful of close provinces like Jaén, Córdoba or Alicante can flip many seats.
- Analysts warn the simulations depend on strict assumptions about voter behavior — that voters mark party slates, that left voters follow the joint list and that former Vox voters back the PP — so real outcomes could differ and would determine control of institutions such as the Constitutional Court and the CGPJ.