The United States has its political power families — the Kennedys, Clintons, Bushes. But nothing quite like what is developing in Poland.

Poland on Saturday faced the almost certain prospect of having identical twin brothers simultaneously hold the posts of prime minister and president in what would perhaps be the most striking feature of the country's ever-chaotic political scene.

President Lech Kaczynski, who took office in December after winning the post in October, was preparing to swear in his twin, Jaroslaw, as the head of a new Cabinet after Prime Minister Kazimierz Marcinkiewicz submitted his resignation to the governing Law and Justice party on Saturday.

Since the socially conservative party won elections last fall, Jaroslaw Kaczynski has used his role as chairman of it to guide the government — but always from the sidelines. It was the popular Marcinkiewicz who represented the government in Brussels and other foreign capitals.

But the two apparently fell out over Marcinkiewicz's choice of a new finance minister, and on Saturday party officials accepted Marcinkiewicz's resignation and said they had chosen Kaczynski to replace him. Kaczynski said at a news conference that he accepted the nomination.

Marcinkiewicz still has to submit his resignation to the president for the change to become official, but it was expected to be merely a formality that the outgoing premier said he would take care of on Monday.

The prospect of having identical portly, gray-haired 57-year-old twins in the two top posts has loomed as a possibility since Lech embarked on his presidential campaign last year.

But Jaroslaw had pledged during the campaign that he would refrain from becoming prime minister to help his brother's shot at the presidency, saying he wanted to spare the country the confusion of identical leaders.

Though both men have the same round faces and short, stout builds, many Poles have learned to distinguish them thanks to the fact that Lech has two telltale moles on his face and wears a wedding ring. The unmarried Jaroslaw has neither.

As quirky as the situation might seem to outsiders, the strangeness of two identical men dominating the political scene has worn off to some extent for Poles, in part because the two have been a public presence for nearly half a century.

The twins — who also happen to be Geminis — first won fame as child actors in the 1962 hit film "The Two Who Stole The Moon." Though their show business careers stopped there, they became politically active when they joined the anti-communist opposition in the 1970s, and later served as advisers to the Solidarity movement in the 1980s.

After the fall of communism, they served briefly as advisers to Solidarity leader Lech Walesa during his 1990-95 presidency, but later fell out with him.

Jacek Kucharczyk, an analyst with the think tank Institute of Public Affairs, says that even if their looks might sow confusion for foreign dignitaries, the issue no longer looms as a domestic predicament.

"It was a kind of aesthetic problem during the elections, and some people thought it was strange looking," Kucharczyk said. "But the main problem is their track record in politics. Ever since they won the elections, they have been destabilizing the Polish political scene. We are in a state of political crisis."

Since Law and Justice formed a government in October, Poland has been beset by political instability and bickering. Attempts to form a coalition with the pro-business Civic Platform collapsed in the fall, and after months of serving as a weak, minority government, Law and Justice stabilized its government by forming a coalition with two Euro-skeptic parties in May.

That deal, however, sparked controversy because of the reputation of the two small parties.

The farm-based Self-Defense is led by Andrzej Lepper, a rowdy former leader of anti-EU street protests that at times turned violent in the 1990s.

And the League of Polish Families has sparked protests because of its close links with a far-right radical youth movement, All-Polish Youth, that has attacked gay rights parades and whose members have been known to use Nazi gestures.