MADRID - Spain entered a governing void Monday, facing weeks or months of uncertainty over what political party or parties will lead the country following a national election that fragmented the status quo. The result was so blurred that a German government spokeswoman said it was impossible to determine who deserved congratulations.

Although the ruling right-of-center Popular Party won the most votes, it failed to retain its parliamentary majority and will try to cobble together a coalition or minority government.

But that's unlikely, analysts say, because the party wouldn't get enough seats in the lower house of parliament even by allying itself with the new business-friendly Ciudadanos party that came in fourth place and is seen as the most likely ideological partner.

The ambiguous outcome pushed Spain's benchmark stock index down 3.6 percent in Madrid as investors fretted over the possibility of a governing alliance between the Socialist Party and the country's new far-left Podemos party.

That sort of combination could lead to a government that would try to roll back highly unpopular austerity measures imposed over the last four years by Prime Minister Mariano Rajoy.

He vowed after the vote to try to form a government, but gave few details on how he would do so after winning just 123 seats in the 350-member lower house of parliament.

Rajoy tweeted he would try to "form a stable government in the general interest of all Spaniards." He then told reporters Monday night he would initiate talks soon to do so, without naming which parties he would seek support from.

German government spokeswoman Cristiane Wirtz said Monday that Spaniards deserve congratulations for voter participation of 73.2 percent, up from the 68.9 percent turnout in 2011 that gave Rajoy a 189-seat parliamentary majority.

"But otherwise, I don't yet see so clearly who one can congratulate in this situation," Wirtz said, adding that no one from Germany's government had contacted Spanish officials about the formation of a new government.

If forced from power, Rajoy and the Popular Party would become the third European victims this year of a voter backlash against austerity - following elections in Greece and Portugal seen as ballot box rebellions against unpopular tax hikes and spending cuts invoked during the eurozone's debt crisis.