ATHENS, Greece – Talks to form a governing coalition in crisis-struck Greece are planned today but the chances of success have been diminished after one leftist party pulled out of the talks, leading the country one step closer to new elections — and bringing its continued membership in the European Union into serious doubt.

Last-ditch efforts by President Karolos Papoulias to broker a deal between wrangling party leaders ended with no deal in sight late Sunday, a week after national elections produced a deadlock, with no party winning enough seats to form a government.

The Radical Left Coalition (Syriza) party, which came in a surprising second in the May 6 election, announced around midnight Sunday it would refuse to join a coalition government.

“Syriza refuses to be a left-wing alibi for a government that will continue the policies the people rejected on May 6,” NET state television quoted Syriza leader Alexis Tsipras as saying.

That leaves conservative New Democracy, which won the election with 18.9 percent, socialist PASOK, which came in third with 13.2 percent, and Democratic Left, the most moderate of the leftist parties, seventh with 6.1 percent, as the only remaining partners available for a coalition government.

In theory, they could form a stable coalition government, but all three have said they would refuse to join a broad coalition government without Syriza.