LISBON — As center-left Prime Minister António Costa enjoys the wind in the sails of Portugal's economy, his opponents complain bitterly that he's benefiting from their hard work.

“The reality is simple: this year we’re going to have the best economic growth this century,” Costa told Socialist Party (PS) supporters this week in the eastern city of Portalegre. “We get better results than the right.”

Such comments rub salt in the wounds of the center-right Social Democrats (PSD), whose leader Pedro Passos Coelho is the man Costa replaced as prime minister in November 2015.

Costa has little to worry about in nationwide elections this Sunday, which will pick mayors for the country’s 308 cities and towns. The Socialists look likely to increase their tally of 150 mayors, keep control in Lisbon and run a close race against the current independent centrist mayor of second city Porto. Barring a major upset, there’s little chance the elections will hurt Costa’s national standing.

The mid-term prime minister is riding high in opinion surveys on a slew of rosy economic news. Growth is bouncing along at 3 percent, the budget deficit has fallen to a record low of 1.9 percent, and on Sept. 15, S&P became the first of the major ratings agencies to grant investment status to Portuguese bonds, more than five years after declaring them “junk” when the country was mired in the eurozone debt crisis.

The vote is much more of a worry for Passos Coelho. A poor showing Sunday will likely see a challenge to his leadership of the Social Democrats.

The PSD faithful say Costa is reaping the benefits of tough decisions taken by Passos Coelho’s administration, and has hit luck with a tourism and export boom fueled by the strong recovery in Spain and other European trading partners.

“All these benefits that we’re getting now are the results of the work that we did in government,” Teresa Leal Coelho, the PSD candidate for Lisbon mayor, told POLITICO. “We got over all of the obstacles and we achieved extraordinary results.”

Pragmatic people

“PSD activists tend to be very pragmatic, they tend to back people who offer the prospect of victory,” said José António de Passos Palmeira, a political scientist at the University of Minho. “A bad result for the PSD would increase pressure on Passos Coelho, it could accelerate his departure from the leadership.”

Passos Coelho actually beat Costa in the last parliamentary election in October 2015, but he lost power when the Socialist leader struck an unprecedented deal with two far-left parties — the Portuguese Communist Party and the Left Bloc — to back a minority PS government.

Since then, the Social Democrats have seen their poll ratings slump. The leadership remains tainted by unpopular austerity policies introduced during Passos Coelho’s stint as prime minister at the behest of international creditors who stepped in with a €70 billion bailout to save the country from bankruptcy in 2011.

In Lisbon, mayoral candidate Leal Coelho is confident of pulling off a surprise on Sunday, but polls suggest otherwise. She is forecast to come third in the capital behind Socialist incumbent Fernando Medina and Assunção Cristas, the leader of a smaller conservative force, the CDS-People’s Party. Cristas served as agriculture minister in Passos Coelho’s government.

The Socialists may struggle to keep their absolute majority in the capital’s council chamber, won in 2013 by Costa, who stepped down as mayor to run for prime minister. However, Medina would almost certainly stay on as mayor with the backing of the far left.

In Porto too, the once-dominant PSD is seen coming third as the Socialists battle for the mayor’s office with the independent incumbent Rui Moreira. Across the country, there’s little sign the Social Democrats can improve on their current tally of just three of the 15 most populous cities.

Passos Coelho insists the result won’t call his leadership into question. However, he’s called a meeting of the party’s national council two days after Sunday’s vote, heightening speculation of a leadership change.

Challengers are sharpening their knives. “Up until the municipal elections, it’s imperative that we look for unity. From the moment that the local elections are resolved, we can fix other issues,” Rui Rio, a silver-haired former mayor of Porto and leading challenger for the PSD leadership told reporters last week.

Controversial candidate

As the center right searches for a way to turn around its prospects, media attention has zoomed in on a PSD candidate in Loures, a sprawling mix of industrial and dormitory suburb on the northern edge of Lisbon. André Ventura has drawn comparisons to Donald Trump and Marine Le Pen after launching a series of campaign attacks on the local gypsy community.

A television football pundit, Ventura has claimed “gypsies live almost exclusively on state handouts,” suggested they should be denied social housing and urged they be forced to take re-education classes on respect for human rights and the law.

Although some Social Democrats — including Lisbon mayoral candidate Leal Coelho — have denounced him, the party leadership has stood by Ventura. Luís Montenegro, another likely contender in the race to replace Passos Coelho, joined Ventura on the campaign trail Monday.

In a country that, together with neighboring Spain, has been almost alone in escaping Europe’s recent surge in far-right populism, there is concern that a good showing for Ventura could signal a radical shift by the PSD. “This could be a trial balloon for a new strategy of political action,” Costa warned in a recent interview with the Diário de Notícias newspaper.

If that’s true, the people of Loures could be poised to shoot it down.

The city is on course to remain a Communist stronghold, according to a poll published Saturday in the weekly Expresso newspaper, with the Socialists in second place. Ventura is forecast to finish a distant third with 18 percent of the vote, just marginally higher than the PSD’s score there four years ago.