ATHENS — Hours after the government won a crucial confidence vote that made it more likely that Greece would receive the foreign aid it desperately needs, the country’s leaders on Saturday reverted to the type of political wrangling that threw Europe and its markets into turmoil last week.

Prime Minister George Papandreou took the first steps Saturday to try to form a unity government with the opposition, which he said was necessary to steer the country out of danger. But by Saturday evening, the two sides seemed locked in position, with the prime minister making no immediate move to leave power — a key demand of the opposition — and the opposition leader reiterating his call for early elections and branding Mr. Papandreou “dangerous for the country.”

While such stands may be nothing more than clever negotiating strategies to win concessions, any sign that Greece may be headed for a poisonous stalemate is sure to rattle other European leaders — and creditors — craving stability.

The continued political upheaval comes at a time when Europe can least afford it.

The European Union wants the Greek Parliament to approve a new debt deal as quickly as possible to guarantee continued foreign support and avoid the risk of default on its debts. To the extent that the financial crisis is partly a matter of perception, any delay would be problematic. But with Italy already at risk, analysts say, further delay could be disastrous, allowing the contagion to spread there.