David Beckham might have felt like a political football when rival Spanish clubs Real Madrid and Barcelona were bidding for him earlier this year, but he was not the only one. The protagonists in Gas Natural SDG's proposed €27bn ($31bn) takeover of utility Iberdrola were also kicked about in the longstanding regional struggle.

The battle for Iberdrola, which sparked a fight between Repsol, the oil giant that owns 25% of Gas Natural, and the other large shareholder, savings bank La Caixa, was seen by many as an extension of the rivalry between Madrid and Barcelona, where La Caixa is based.