Spain’s first televised electoral debate in 15 years has proved a hit, with an estimated 13m viewers tuning in to the clash between José Luis Rodríguez Zapatero, the prime minister, and opposition leader Mariano Rajoy.

At one stage about 60 per cent of all televisions in the country were tuned to the exchange, making it almost as popular as past football finals between top Spanish clubs and their European opponents. The debate was the first of its type since the 1993 clash between Felipe González, the socialist reformer, and José María Aznar, the conservative who went on to lead the country between 1996 and 2004.