Ukrainian opposition leader Viktor Yushchenko (search) warned a rally of thousands of his supporters in frigid central Kiev on Wednesday that forces were planning to disrupt the rerun of the presidential runoff.

He also praised the crowd for changing the country without bloodshed. The demonstrators chanted "Yu-shchen-ko! Yu-shchen-ko!" and proudly displayed their candidate's campaign color by wearing orange armbands and waving orange banners.

"The vote on Dec. 26 will not be an easy political walk," Yushchenko told the crowd gathered on Independence Square to mark one month since the beginning of the "orange revolution" opposition protests. "There are some forces preparing to disrupt and they are preparing brigades, groups who are preparing to come to Kiev."

He did not say who was allegedly plotting to disrupt the vote, but told his supporters he was "calling on your courage to defend the results of the election."

"We will come on this square, this stage after the vote on Dec. 26 and will stay until our victory is celebrated," Yushchenko said.

He told the crowd that they "peacefully, beautifully, elegantly and without any drops of blood changed Ukraine.

"You should applaud yourselves because in this difficult period, we didn't stay in our apartments ... but came to the square," he said.

Yushchenko was flanked on the stage by top opposition leaders as well as the country's famous boxers, Vitaliy and Vladimir Klitschko.

For almost three weeks following the Nov. 21 presidential runoff, Independence Square was the scene of massive protests that paralyzed the government in this ex-Soviet republic. Hundreds of thousands rallied, setting up a sprawling tent camp on the tree-lined main street, bringing central Kiev to a halt.

The Supreme Court later threw out the results of the runoff, citing mass fraud, and annulled Prime Minister Viktor Yanukovych's (search) victory. The court ordered a new vote to be held Sunday.

"Those were really revolutionary days — so much work to change a hated regime has never been done before," said Yushchenko, wearing a trademark orange scarf. "This history lesson will never be forgotten."

2004 became "the year of Ukraine in the world," he said.

Referring to the revote, Yushchenko said: "The doors have been opened. The only thing left for us is to step over the threshold."

Earlier Wednesday, Yushchenko said that attempts to make Russian the country's second official language had become a political issue — a remark likely to anger voters in the Russian-speaking east who support his opponent.

But Yushchenko also sought to assuage their worries by pledging to make Russia his first official destination if he wins on Sunday.

"Ukraine will maintain good relations with Russia, but also with the European Union," Yushchenko said in a statement posted on his Web site.

In an interview with Russian media, Yushchenko also ruled out naming Yanukovych to any Cabinet position.

"We aren't considering under any circumstances the possibility of Yanukovych's participation, such as Yushchenko president and Yanukovych as prime minister or any other position in my government," Yushchenko was quoted by the Interfax news agency as saying.

During a televised debate Monday, Yanukovych appeared to suggest that possibility when he said that Yushchenko would never be considered president of all Ukraine and that he should seek out compromise.

The campaign has split Ukraine (search), and the issue of language has become key. Almost 70 percent of the population uses Russian on a daily basis, but it prevails in the east and south — regions that back Yanukovych and have close historical ties with Russia.

Ukrainian is spoken mainly in the west, although the two languages are very similar.

Yanukovych wants Russian given official status alongside Ukrainian, which is constitutionally protected as the language of government, the police and military, universities and most schools.

Russian-language schools are widespread, and most children are bilingual. But Yanukovych supporters fear a Yushchenko presidency would lead to Ukrainian being promoted at the expense of Russian, leading to discrimination in employment and other areas.

In other former Soviet republics with large Russian-speaking populations, such as the Baltics, Russian has been marginalized by efforts to promote native languages.