Former Prime Minister Yulia Tymoshenko announced in parliament Thursday that she and other allies from Ukraine's Orange Revolution had reunited into as a majority coalition and would start forming a government.

"Today we start our struggle so that our country can be democratic," Tymoshenko said. "We were given a second chance, and ... if we don't use this second chance, then the Ukrainian people will say it serves us right."

The coalition of pro-Western reformers who aim to move the former Soviet republic out of Russia's shadow was formally accepted after their names were read out in parliament.

The parties will hold a 243-seat majority in the 450-member parliament. Their next task was to begin naming the Cabinet, but Tymoshenko said that would not happen before Tuesday.

The three parties have struggled for nearly three months to overcome differences on economic and foreign policy issues and lingering distrust after their first union collapsed.

They have pledged to pursue the general reformist and pro-Western program adopted by President Viktor Yushchenko, who came to power after the Orange Revolution. The deal would bring back Tymoshenko, whom Yushchenko fired in September after he said her populist policies had brought the country to the verge of economic ruin.

On Thursday, Tymoshenko promised "a smart and predictable economic policy," and she immediately called to review the controversial gas deal forged with Russia earlier this year.

For some Ukrainians, the return of the charismatic Tymoshenko was a welcome development.

"My respect for Tymoshenko has even deepened," said military surgeon Yuriy Shevchuk, 48. "She looks so small and tender but she is the only man among the politicians."

The new government, when formed, will face considerable hurdles.

Its members campaigned against each other in the March elections, and they have a thin majority that could prove hard to hold together on controversial issues such as cooperation with NATO.

The Party of Regions, the pro-Russian party that will be the main opposition, has signaled that it won't give the new government an easy ride; on Thursday, its lawmakers initially claimed that the new coalition had forged some of the lawmakers' signatures on the agreement.

Viktor Yanukovych, who leads the Party of Regions, had hoped to put together a pact with Yushchenko, his 2004 presidential rival. As Tymoshenko spoke, Yanukovych looked distraught, sitting with his chin in his hands.

Under Ukraine's constitution, the new coalition has 30 days to name the Cabinet. But the agreement makes clear that Tymoshenko will be prime minister, and Yushchenko's party gets to pick the parliamentary speaker — the second most powerful job. They've put forward former Security chief Petro Poroshenko, whose bad relations with Tymoshenko led to the Orange team's breakup last year.

The candidates still must be approved by parliament, and if any significant number of lawmakers rebelled against their parties' course, the approval could be at risk. At least one Socialist party lawmaker said he would refuse to vote for Tymoshenko as prime minister.