Russia gas deal collapses

An EU-brokered accord on terms for Russia to resume gas supply to Europe collapsed when Russia accused Ukraine of secretly altering the deal and declared it null and void.

"I am ordering the government not to accept the document signed yesterday," Russian President Dmitry Medvedev said in televised remarks.

"We are obliged to consider the document signed as null and void."

The breakdown came as a huge swath of central Europe suffered for a sixth consecutive day from the abrupt cutoff of Russian natural gas supplies that has left homes without heat and idled factories and schools.

The dispute between ex-Soviet giants Russia and Ukraine over gas payments and prices has presented the EU with one of its worst-ever energy crises and has raised urgent questions about the reliability of supply from Russia.

Medvedev and other senior Russian officials including Prime Minister Vladimir Putin charged that Ukraine had added phrases to the accord already signed by Russia and the EU that eviscerated the accord of its purpose.

Putin telephoned European Commission President Jose Manuel Barroso and informed him that the modifications introduced by Ukraine were "unacceptable" to Russia, the government's press service said in a statement.