David Cameron has instructed his ministers to stay away from the Sochi Paralympics because of escalating tensions between Russia and Ukraine, while several national Paralympic associations are discussing whether their athletes should still take part.

After an announcement by the foreign secretary, William Hague, that the UK was withdrawing from preparatory talks before the G8 summit in Sochi, scheduled for June, Cameron tweeted: "Because of the serious situation in Ukraine, William JHague & I believe it would be wrong for UK ministers to attend the Sochi Paralympics."

Following Cameron's announcement Buckingham Palace said Prince Edward had pulled out of the Paralympics on the advice of the government after Russia's decision to take military action in Ukraine. The prince is patron of the British Paralympic Association and was due to attend the Sochi Games for three days next week.

Russia, meanwhile, got in a little retaliation against the west when its main television channel announced it would no longer show the Oscar ceremony. It said in a statement: "Due to the large amount of news concerning the situation in Crimea and the Ukraine and the audience's rising interest in news programmes, Channel One considers it impossible to air the Oscars ceremony for five hours, particularly in the morning."

None of the 44 countries taking part in the 11th Winter Paralympics, which open on Friday, have yet hinted at withdrawal, but a number are monitoring the situation.

The Russian venue, which has just finished hosting the Olympics, is less than 300 miles from Simferopol, Crimea's administrative capital, although there are no immediate security fears for the 700 participating athletes. However, should the situation escalate significantly in the next few days some Paralympic associations could come under political pressure to reconsider.

A British Paralympic Association said there had as yet been no change of plan for its 15 athletes. A spokeswoman said: "We are clearly monitoring the events in Ukraine and continue to be in close contact with the Foreign Office, who are leading on security matters."

A spokeswoman for the US Olympic Committee, which deals with Paralympic matters, said: "Nothing has changed in our planning. We are looking forward to a great 2014 Paralympic Winter Games."

In a statement on Saturday the International Paralympic Committee said it hoped to see Russia adhere to the Olympic truce, a tradition backed by a UN resolution that asks nations to cease hostilities during the Olympics and Paralympics. It said: "We want the story here to be the great festival of sport that has already taken place in Sochi and will continue now that athletes are arriving for the start of the Winter Paralympics."

Russia experienced a lesser degree of political pressure over the Sochi Olympics, mainly connected to its law against disseminating gay "propaganda" to children and wider human rights issues. Britain was represented by the relatively lowly culture secretary, Maria Miller, rather than Cameron, seen as something of a snub since London had held the previous Games. Other leaders to stay away included Barack Obama, Angela Merkel and François Hollande.

The concept of the Olympic truce, codified by a UN resolution in 1993, came in the wake of the tit-for-tat boycotts of Summer Olympics that badly affected the 1980 and 1984 Games. Dozens of nations withdrew their athletes from the 1980 Moscow event in protest at the Soviet invasion of Afghanistan, including the US, West Germany and Canada. British athletes took part, despite domestic political pressure to stay away.

Four years later in Los Angeles the Soviet Union and more than a dozen other communist nations and allies opted to not compete, officially because of fears about anti-Soviet feeling in the US.