UKRAINE was plunged into political turmoil last night after the parliament voted to sack the Government that reached a controversial gas deal with Russia. But the Prime Minister and his Cabinet insisted that they would not stand down.

The vote left President Yushchenko’s Orange Revolution, hailed as a democratic breakthrough in the former Soviet bloc, deep in crisis.

The parliament voted 250-50 to support the surprise no-confidence motion, largely inspired by Yulia Tymoshenko, the former Prime Minister, who was the President’s key ally in the Orange Revolution but who was dismissed by him in September.

Mr Yushchenko declared the vote unconstitutional. “This cabinet will work until the parliamentary election [in March]. I want to underline, they will not be caretakers but will work as Prime Minister and ministers of the Cabinet,” he said in a statement.

Yuri Yekhanurov, the Prime Minister, also declared that he would continue in his post.

The legislators had argued that they were using powers given to them by the new constitution to protest against the deal that the Government made last week with Moscow, which will nearly double the price paid bu Ukraine for Russian natural gas.

The crisis is likely to be seen as a partial victory for President Putin of Russia, who has been accused of engineering the gas row to destabilise the pro-Western Government before elections.

Under sweeping constitutional reforms adopted last year, the parliament can appoint the Cabinet and sack individual Cabinet ministers. However, the Government claims that the parliament has no power to sack the Prime Minister or the Cabinet.

Political analysts were divided on the matter. Serhiy Holovaty, the Justice Minister, told reporters that a new Cabinet can be chosen only by parliament after the elections, due to be held on March 25: “The absurdity of the situation is that neither the President nor the parliament will be able to form a new government until a new parliament is elected.”

Nestor Shufrych, an opposition politician of the Social Democratic Party, acknowledged that the parliament’s resolution had no legal power.

“Yes, we know that we cannot dissolve the Cabinet . . . we are familiar with the constitution. We deprived the Cabinet of the opportunity to make decisions,” he said.

Even if it does not lead to the immediate collapse of the Government, the turmoil is unlikely to displease Mr Putin. He tried in vain to stop Mr Yushchenko, who is keen on closer ties to the EU and Nato, from coming to power.

The vote is also a triumph for Mrs Tymoshenko, who will now be standing against Mr Yushchenko’s allies in the elections. She was seen to be the driving force behind the no-confidence vote in an unholy alliance with pro-Moscow MPs who were supporters of the pre-revolution government.