Yulia Tymoshenko, Ukraine's ex-prime minister and now main opposition figure, has warned President Viktor Yanukovych she will keep up the pressure on the new government, especially over its energy plans.

"It seems to me they have already loosened up and will begin corrupting the constitution, the laws, taking away what I returned to the state. I don't want this to happen - the new government will have to account for its actions in front of the public every day," Tymoshenko said in an interview published in the Russian daily Izvestia on Friday.

Tymoshenko said the opposition would be particularly tough on three points of Ukraine's energy policy.

She said she would not allow the new president to create a consortium for the transit of gas, or to compromise with Russia in the sensitive issue of gas pumped into Ukrainian underground storage facilities last winter.

"The gas pipeline system will remain the property of Ukraine and will make our country strong," she said.

"If Yanukovych raises a hand to return the 11 billion cubic meters of gas that supposedly belonged to RusUkrEnergo, we will fight so this does not happen," she added.

Tymoshenko also said the opposition would closely watch for any sign that Yanukovych favored certain groups in the possible privatization of gas deposits controlled by Ukraine on the Black sea shelf and near Russia's Far Eastern Sakhalin Island.

Tymoshenko, narrowly beaten by Yanukovych in the presidential election last month, is working to forge a strong opposition to the new government. She has already branded as "illegitimate" the government of Prime Minister Mykola Azarov, which was recently approved by a majority vote in the parliament.

KIEV, March 12 (RIA-Novosti)