An official poll released on Wednesday by the state-run Sociological Investigation Centre (CIS) gave the ruling Popular Party 28.2 percent of the vote, a clear three points ahead of the Socialist (PSOE) opposition and a rise of 2.6 points from the last similar poll in May.
Spain's newest parties, the radical anti-austerity party Podemos and the centrist Ciudadanos, have both lost support since the last poll in May, securing just 15.7 percent and 11.1 percent respectively.
However, while the findings will give a boost to the ruling PP, it shows the party is still far short of securing the majority it won in the last general election in November 2011, meaning pacts will have to be sought come elections at the end of the year.
Podemos, which surged onto the political scene last year, has been losing momentum since voting intentions gave it almost 25 percent of support in a poll on voter intentions in January.
Candidates backed by Podemos enjoyed success in the recent regional and municipal elections in May, winning mayoral seats in Spain's three largest cities of Madrid, Barcelona and Valencia.
The split vote meant that although the PP won the most seats in nine out of the ten semi-autonomous regions that went to the polls in May, they stayed in government in only four of them.
The arrival of new parties on the political scene has been heralded as the end of Spain's traditional two-party system, but the recent poll showed that as the general election approaches, more voters are returning to the two main parties.
Spanish conservative-leaning daily El Mundo reported the poll findings with the headline "Bipartisanism begins its comeback".
Unemployment was Spaniards' main concern in the poll, followed by corruption. Spain's unemployment rate of 22.4 percent is the second-highest in the European Union after Greece's.
The poll was based on 2,486 interviews made across Spain between July 1st and July 9th.