By David Román 

MADRID--Spanish Prime Minister Mariano Rajoy announced a 1% wage increase for Spain's civil servants on Friday, the first in five years, as he unveiled a government budget for 2016 that seeks to address austerity fatigue in the run-up to parliamentary elections.

The budget, to be presented to parliament on Tuesday, includes a 0.25% increase in monthly payments for pensioners, a reliable voting bloc for Mr. Rajoy's conservative Popular Party.

The Spanish leader also announced that EUR750 million ($831 million) in bonus payments for civil servants would be distributed in three batches--one in September and two next year. Spain's three million civil servants make up about 14% of the workforce. The bonus payments were frozen between 2012 and 2014.

"It is time to give back to society, after all the sacrifices in all these years," said Mr. Rajoy, who is seeking re-election in what is expected to a close race against leftist critics of his government's austerity measures. "That effort has allowed us to keep our welfare state in place."

Taking office in late 2011, Mr. Rajoy's government raised taxes and cut spending to confront Spain's worst recession in decades. The economy began growing two summers ago but unemployment remains among the highest in Europe, at 22.4%

Mr. Rajoy, speaking to reporters after a cabinet meeting, said that the proposed budget marks the end of a painful period of cuts.

Patxi López, a senior official in Spain's opposition Socialist Party, called the wage and pension increases a last-minute offering of "little sweets for kids" that seeks to buy votes. He said that the financial commitments will tie the hands of the next government.

Mr. Rajoy must call the election by the end of this year. At Friday's news conference, he dodged a question about its date.

Ireland and Portugal, which like Greece received European Union bailouts, have also chafed under unpopular austerity measures. Portugal has vowed to boost government spending, as Ireland is doing this year. Portugal will hold a general election on Oct. 4, and Ireland must hold one no later than next spring.

Mr. Rajoy's party leads opinion polls with 27% of likely votes, according to an average of several surveys over the past month compiled by the Politikon think tank. But the center-left Socialists and the far-left Podemos party--likely to ally in parliament if they secure enough seats together to topple Mr. Rajoy--are polling 24% and 18% of likely votes, respectively. Ciudadanos, a center-right party that is a possible coalition partner for both Mr. Rajoy's party and the Socialists, is fourth with 12%.

Like its EU partners, Spain faces budget deficit limits and is committed to achieving a primary budget surplus, excluding debt servicing costs. Mr. Rajoy said on Friday that Spain expects to post a primary surplus of 0.1% of gross domestic product in 2016, its first in eight years.

Spain's statistics institute said on Thursday that the economy expanded 3.1% in the second quarter of this year, over the same period last year, the fastest rate since the start of a property bust that sent the economy into a tailspin in 2008. That growth underpins Mr. Rajoy's plan to expand the central government budget next year--to EUR351.9 billion, up 1.2% from this year's budget--while cutting the deficit.

However, independent economists say that election-year spending promises by the central and regional governments will make it hard to meet Spain's budget deficit targets--4.2% of gross domestic product this year and 2.8% of next year.

"We are also concerned about near-term fiscal pressures, and expect the general government budget deficit to stand at 4.8% of GDP in 2015 and 3.6% in 2016," said Raj Badiani, an economist with IHS Group.

Write to David Román at david.roman@wsj.com