TENSIONS in the Ukraine reached boiling point this week after President Putin signed a law that decreed that Crimea was Russian territory.

The law was expected to come into force this week, after being ratified by the constitutional court in Moscow, and approved by the Russian parliament, the Duma. It follows the disputed referendum on Sunday, in which residents of the peninsula voted to secede from Ukraine.

"In people's hearts and minds, Crimea has always been an inseparable part of Russia," President Putin told Russian and Crimean parliamentarians on Tuesday. He said that the decision by Nikita Khrushchev to give Crimea to Ukraine in 1954 was to "win the support of the Ukrainian political establishment, or to atone for the mass repressions of the 1930s.

"This decision was made inclear violation of the constitutional norms that were in place even then. The decision was made behind the scenes. Naturally, in a totalitarian state, nobody bothered to ask the citizens of Crimea and Sevastopol."

Mr Putin said that the decision was treated as a formality because "the territory was transferred within the boundaries of a single state. Back then, it was impossible to imagine that Ukraine and Russia may split up and become two separate states."

He said that after the collapse of the Soviet Union, "It was only when Crimea ended up as part of a different country that Russia realised that it was not simply robbed, it was plundered."

Within minutes of his speech, skirmishes broke out at military bases on the peninsula, which had been blockaded by Russian forces for weeks. Initial reports suggested that Russian troops were seeking to take the military bases by force, but these proved to be inaccurate. One Ukrainian soldier was killed; another is in hospital after being attacked.

In Britain, the situation in the Ukraine was the subject of emergency debates in both the Commons and the Lords. The Foreign Secretary, William Hague, described the "crisis" as "the most serious test of European security in the 21st century so far".

He condemned President Putin's speech, saying: "No amount of sham and perverse democratic process or skewed historical references can make up for the fact that this is an incursion into a sovereign state, and a land-grab of part of its territory, with no respect for the law of that country or for international law."

The Shadow Foreign Secretary, Douglas Alexander, said that it was "the most significant security threat on the European continent in decades", and a "real threat to Ukrainian sovereignty and territorial integrity".

The Bishop of St Albans, Dr Alan Smith, gave peers a potted history of Christianity in the Crimea, and the divisions within Ukraine's Churches, before turning to the events of the uprising in Kiev that sparked the current situation. He described the protests in Independence Square as a "uniquely ecumenical and interfaith phenomenon".

Religious communities in Ukraine had "been extremely supportive of the political aspirations of the demonstrators", and many religious organisations in the country were members of European bodies, including the Conference of European Churches, and the Federation of Islamic Organisations in Europe.

The "barriers of mistrust" between different Churches had "started to erode" since the crisis began, and "some religious leaders [have] actually started talking to one another".

Dr Smith said that if the Kiev and Moscow Patriarchates of the Ukrainian Orthodox Churches were able to "reconcile differences and unite in one Church" (News, 14 March), it would "redraw the map of Orthodoxy, as "Ukraine is the second-largest Orthodox country after Russia. The critical distance that has already emerged between the Ukrainian Orthodox Church and the Russian Orthodox Church in Moscow is significant."

Western governments are increasing their pressure on Moscow. The Council of Europe is expected to sign a security and co-operation agreement with Ukraine today; and will also discuss a third-tier of sanctions against Russia. These are expected to include the cancellation of an EU-Russia summit.

Preparations for this year's meeting of the G8 - which was due to take place in Sochi - have been suspended. The G7 will meet informally next week in The Hague and could announce plans for an alternative G7 summit outside Russia.

Should Russia be allowed to keep Crimea?

Vote here