Spain’s opposition Popular party hopes to win a general election in nine days’ time by persuading Socialist sympathisers to abstain.

“Our whole strategy is centred on wavering Socialist voters,” Gabriel Elorriaga, a senior strategist at the conservative party, says. “We know they will never vote for us. But if we can sow enough doubts about the economy, about immigration and nationalist issues, then perhaps they will stay at home.”

The Popular party (PP) needs a high abstention rate to win. Mr Elorriaga says the party faithful are all fired up to vote, but admits that the PP has been unable to broaden its appeal during its four years in opposition. “It will be difficult to increase our vote,” Mr Elorriaga says. “The PP has a very hard, rightwing image at the moment. Even our own voters think they are more centrist than the PP.”

By contrast, the Socialist party has a far broader base. “But their voters are less disciplined than ours,” Mr Elorriaga says. “That is why we are directing our message at them. We are saying, ‘your government has not taken care of your problems’. The election result will depend on the impact of that message.”

Most opinion polls give the ruling Socialists a lead that is too narrow for comfort. That is because conservative Spaniards tend to conceal their true voting intentions. Pollsters say they try to account for this idiosyncrasy, but in a tight race, the impact of the PP’s “hidden vote” is difficult to gauge.

As the election campaign began in earnest this week, José Luis Rodríguez Zapatero, the Socialist prime minister, has had only one goal – to get out the vote. In a private remark to a tele­vision anchorman that was caught on tape, Mr Zapatero confided: “We are relaxed about the polling data, but we could benefit from a little more crispación [confrontation].”

Mr Zapatero’s comment explains a stunning role reversal in the run-up to the elections. During the past four years, Mr Zapatero has depicted himself as a leader of dialogue and consensus, while the conservatives, by their own admission, have kept their supporters angry and mobilised by deliberately seeking crispación.

Now it is Mariano Rajoy, the opposition leader, who is preaching consensus as Mr Zapatero’s gloves come off.

In an effort to sound reasonable to Socialist sympathisers, Mr Rajoy’s message at a campaign rally in Santa Cruz de Tenerife, in the Canary Islands, was all about inclusiveness. “I am ready to be your prime minister, and I want my project, which is also yours, to be one that all Spaniards can feel comfortable with,” Mr Rajoy said. “I don’t want divisions, or tensions, or crispación.”

According to Mr Elorriaga, the PP believes it can do most damage to the Socialist party by attacking its record on the economy, which is slowing, and on immigration, which is rising.

The PP is also relying on old-fashioned populism. The tax cuts it is promising – including a lower tax rate for working women – are more generous than those in the Socialist manifesto. The PP has also promised to bail out some 300,000 Spaniards who lost €5bn ($7.6bn) in a fraudulent stamp investment scheme.

The Socialist government shut down two companies in 2006 that traded in “investment grade” stamps after they had lured investors with offers of guaranteed returns. But as the investments were not insured, the government has not compensated the stamp collectors for their losses.

The PP has also latched onto growing concern about immigrants – who now number more than 4.5m, or 10 per cent of the population – in an economic downturn. In Tenerife, Mr Rajoy told supporters Spain needed tougher controls because “there is no room for so many immigrants”.

But Mr Rajoy’s own record at controlling illegal immigration when he was interior minister in the last PP government was dismal. Instead, he has focused on the problems of integration. Mr Rajoy says a PP government would oblige immigrants to sign an “integration contract” like those being applied in France, and he would also ban the wearing of Muslim headscarves in schools.

The Socialists accuse Mr Rajoy of creating problems where there are none.

Jaime García-Legaz, director of Faes, a PP think-tank that contributed much of the election manifesto, says the party is right in trying to anticipate problems that may arise in the future. “We have studied the experience of France and the UK with their immigrant populations, to see how it can be adapted to Spain,” he says.

Faes is closely linked to neo-conservative think-tanks in the US, and Mr García-Legaz happily admits that the PP has “borrowed” ideas from abroad for its election campaign.