ROME- Italian voters have spoken. The fat lady, though, ain't singing.

By early Tuesday, after two months of campaigning and two days of voting for national elections, there was little clarity about who would lead Italy. With no coalition earning a working majority in the Senate, and few scenarios imaginable to forge a compromise among competing parties, utter political gridlock seemed likely for the coming days, if not weeks.

Adding to the uncertainty was the remarkable showing of the Five Star movement led by former stand-up comedian turned blogger and political activist Beppe Grillo, whose anti-establishment message struck a chord in an Italy tired of economic crisis and political corruption. Grillo vowed late Monday that he would do "no backroom deals," declaring "war" against the traditional parties. 

Grillo campaigning last month (Roberto Beragnoli)

One prominent center-left leader, Enrico Letta, has already begun to talk about a rapid change to Italy's messy electoral law, and a quick return to the polls, Corriere della Sera reports.

With a razor-thin advantage, the favored center-left coalition could claim victory in the Lower House of Parliament, with less than a one-half percentage point advantage over the center-right coalition led by former three-time Prime Minster Silvio Berlusconi, back one more time from political purgatory. With a system that awards a "majority prize" to whoever finishes first, the center-left led by Pierluigi Bersani was poised to control the Lower House.

But in the Senate, where the same center-left coalition finished with a similarly slight advantage,the electoral law doesn't award the same "majority prize", and no one voting bloc has a workeable majority.

The results are a stunning setback for Bersani, whose coalition was polling above 35% in days before the vote, and yet another case of Berlusconi being underestimated by his opponents.

Berlusconi last spring (PPE)

The election was also a brutal defeat for Mario Monti, the former European Union Commissioner who had arrived in Rome as a "technocrat" caretaker Prime Minister in late 2011. After Berlusconi pulled his support from the interim government, Monti decided to run for office for the first time in his life. He finished with support hovering at around 10%.