DRAMATIC political change is sweeping Spain, or so polling suggests. For three decades Mariano Rajoy’s conservative Popular Party (PP) and the Socialists have taken turns to run the country. Now their support is crumbling (see chart) and a two-party system that guarantees stable governments is at risk. Two recessions in five years and 27% unemployment have shaken faith in the status quo. And as bond markets are getting the jitters again, promises of a return to growth this year have failed to restore shattered confidence. Corruption, cronyism, entitlement and a lack of transparency have helped persuade voters that the system which served their fledging democracy so well has become a liability.

Backing for the PP has shrivelled from 45% to 24%. Yet under Alfredo Pérez Rubalcaba the Socialists have failed dismally to capitalise on the growing discontent. Instead, support has shrunk from 29% in the elections of November 2011 to around 21%. Elections are not due until late 2015, but Spain is on track for its weakest government since democracy was restored in 1977.

If Spaniards want to throw out the old order, what other choices do they have? Two parties are mopping up the discontent. The centrist Union for Progress and Democracy (UPyD), founded by Rosa Díez, a former Socialist, is settling in as the new third party, making her a potential kingmaker at the next general election. Ms Díez blames the two big parties for wrecking the economy by pumping up a property bubble through their joint control of planning laws, regulators, the central bank and reckless savings banks. She bashes nationalists in Catalonia and her native Basque country. She seeks radical internal reform, re-centralising control over health and education and taking privileges away from Basques, Catalans and Navarrans by putting all regions on an equal footing. And, like Britain’s Liberal Democrats, she wants electoral reform to favour her own party.

Ms Díez refuses to rule out future deals with any party except those with ties to ETA, the Basque terrorist group. But she insists on a constitutional overhaul and wants the next parliament to bring it about. “A self-confident democracy revises its laws on the basis of their consequences,” she says. Ms Díez claims UPyD, which has just five deputies, has already pushed political debate towards previously taboo topics such as constitutional reform or reversing devolution.

The other beneficiary of discontent is United Left (IU), a communist-led coalition that has shown surprising flexibility in regional governments. It helped a minority PP government snatch power from the Socialists in Extremadura. But it backed the Socialists in Asturias and is in a coalition with them in Andalusia, one of the largest regions. José Luis Centella, an IU deputy, says these regional deals cannot be extrapolated to national politics.

With future votes spread so widely, dealmaking will decide elections. The Socialists have the advantage. They can ally with IU, UpyD as well as Catalan or Basque nationalists. They could even bring several parties together. Perhaps, given the number of ingredients it may need, Spain’s next government will look like the popular national dish: a paella coalition.