The TU-95 aircraft were spotted on long range radar flying down from Scotland towards the English Channel, where they were close to entering British airspace, the Sunday Express report.

>Ministry of Defence sources revealed the ‘seek and find’ nuclear warhead missile which can destroy the British Vanguard submarines which form the country’s nuclear deterrent.

It led to the incident being described as “yet another in a series of deliberately provocative” actions by Vladimir Putin and shows that the Russians have put NATO countries in the list of adversaries.

The Prime Minister and Defence Secretary were informed of the development after a Norwegian listening post intercepted conversations from the Russian bomber’s cockpit which confirmed the bomber’s nuclear payload.

The missile was not armed, but it is shows the Russians taking the next provocative step in their increasingly chilly relations with the West.

A senior RAF source said, “We downloaded conversations from the crew of one plane who used a special word which meant the would-be attack was a training exercise.

“They know that we can pick up their transmissions and it would only be of concern if the often used release weapon order was changed.

“We also knew from another source that one of the aircraft was carrying a nuclear weapon long before it came anywhere near UK airspace.”

The Russian Ambassador to the UK was summoned by the Foreign Office to account for the incident on Friday, which many say was deliberately planned to coincide with the Alexander Litvinenko inquiry where the two murder suspects are Russians, protected by the Kremlin from extradition to face trial.

While experts have been keen to stress that this is not reigniting cold war tensions between Russia and the UK, it was common practise for Soviet military aircraft to carry nuclear weapons prior to the Communist downfall in 1991. However, it has recently been resumed by Moscow who are facing increased sanctions by Western nations and aligning themselves with countries known to be tense around America and Europe.

Experts from the Royal United Services Institute think tank said the sortie showed Russia was “upping its game” admin the ongoing diplomatic discussions.

“This continual and increasing probing of Nato airspace by these nuclear bombers and fighter aircraft, tankers and electronic aircraft by Russian is a pattern of increased pressure by Russia designed to remind the West and Nato that they remain a large nuclear power, and a serious military power with reach,” said Justin Bronk.

“Russia now clearly perceives Nato not as a potential threat, but as an adversary.

“But this intimidation belies a misunderstanding of the way the West works. As far as our military is concerned, it is helpful for Putin to be stepping up these actions. It serves to remind the public at a time where defence budgets are under pressure that this threat is still real, active and is not going away.”

The news left some calling on the Ministry of Defence to make sure that the UK was properly defended after the last SDSR which drove an axe into the funding and manning of the Armed Forces.

Air Cmdre Andrew Lambert, of the UK National Defence Association said, “We have reduced the number of or Typhoon squadrons to the bare minimum. They have the Quick Reaction Alert commitments, Nato’s Baltic effort, and of course, the Falklands. So we are stretched three ways. We have too few air defence aircraft bearing in mind the commitments we now have.

“When the next round of defend cuts are discussed, it must be realised that we must have enough F-35s so that the our Typhoons can concentrate on their primary role – the air defence of this country.”

Last year, Conservative MP Steve Baker told Breitbart London, “If we only have small numbers of aeroplanes then I think that is an implicit admission that we only ever expect to fight alongside the Americans.”