Britain's communists called yesterday on all signatories of the February 21 agreement on constitutional change in Ukraine — including the European Union — to defend its terms to prevent further violence.

EU chiefs welcomed Friday’s deal, signed by President Viktor Yanukovych as well as opposition leaders including far-right Svoboda Party chief Oleh Tyahnibok.

But they have failed to speak out as the opposition ignored the document, seizing control of Kiev over the weekend.

Communist Party of Britain general secretary Robert Griffiths pointed out that reneging on the agreement “gives sanction to an effective coup d’etat that is creating circumstances of extreme danger for Ukraine and more widely.”

A projected “national unity government” in the offing is tipped to include Svoboda, which organised a 15,000-strong march in Kiev last year to honour nazi collaborator and war criminal Stepan Bandera.

Despite its name it is not expected to include MPs from the president’s party although most of eastern Ukraine remains hostile to the uprising.

The Communist Party of Ukraine’s offices in the capital have been attacked by “well-prepared militants” who smashed windows and damaged furniture.

Gun-toting fascists in organisations such as Right Sector, whose leader Aleksandr Muzychko has pledged to “keep fighting communists, Jews and Russians while blood flows in my veins,” have taken control of much of western Ukraine.

Mr Muzychko warned at the weekend that if his forces saw anyone engaged in “lawlessness” they would “shoot them on the spot.”

His group has not abided by terms of Friday’s deal, in which opposition forces agreed to hand their weapons over to the authorities — though it is not clear that any other groups have either.

Mr Griffiths also condemned a resolution being considered by the rump parliament — many anti-opposition MPs have been attacked trying to take their seats — to ban Mr Yanukovych’s Party of the Regions and the Communist Party.

“Together these parties received 217 of the 445 seats in the most recent democratic elections,” he pointed out.