The risk of an all-out nuclear war is not a far away threat but a «very real possibility,» one of Russia’s opposition leaders has warned.

Grigory Yavlinsky wants to make it clear that Vladimir Putin’s threats of nuclear Armageddon between the East and West are «serious».

Putin’s months of rambling threats of nuclear war means the spectre of the mushroom cloud still looms heavily across Europe and beyond.

Yavlinsky, a former Soviet-era power broker and founder of Russia’s last liberal party, told The Sun Online: «Taking into account the size of the threat of nuclear war — this is all so serious.»

Putin is emerging from the instability of an attempted coup, and the danger of a weakened Vlad «must be taken into account».

The «threat» isn’t just for Ukraine, he warned, but a nuclear apocalypse «between the East and West».

«I wouldn’t say it’s a threat for tomorrow but as far I understand – this is 50/50, this is a very real possibility that can be realised.»

Backed into a corner, Yavlinsky explained that «Putin could be in the position [to use nuclear weapons] if he does not have the vision to find a way out.»

The Yabloko chairman and three-time presidential candidate is one of very few of Putin’s political opponents who hasn’t been exiled, incarcerated or mysteriously killed.

He lives and works in Moscow and knows all too well about the target on his back.

“I am thinking about that everyday, every minute, we can stop the interview and anything can happen, but this is my country.

«I have been working in politics for more than 30 years, and it is my responsibility and obligation to warn about the real danger as I see it,» Yavlinksy said.

Last week, President Joe Biden warned the threat of the tyrant using tactical nukes in Ukraine was “real” — but since then Russia has changed.

Over the weekend, Wagner boss Yevgeny Prigozhin led an armed uprising, vowing to topple Russia’s top brass.

Vladimir threw around the words “mutiny” and “treason”, an airforce plane was shot down, an oil depot blown up and one of the world’s most feared rulers was seemingly caught red-handed fleeing Moscow.

All the while, experts were keen to point out that a trembling, paranoid Putin was still in control of the largest nuclear arsenal on the planet — and they couldn’t totally rule out his fingers lurching towards the button.

Then, just as quickly as it started, the steaming rebellion that was half-way to Moscow was blown out after some murky backdoor deal.

Putin, however, had faced the biggest threat to his regime since he took power over two decades ago — his aura of invincibility torn apart; his grip on power weakened.

The possible crisis of nuclear escalation appeared so serious that US officials — who admitted to having prior knowledge of Prigozhin’s plans — were terrified a nuclear-armed rival was about to descend into chaos.

The writing has been on the wall.

Last September, while Mad Vlad ordered the first troop mobilisation since World War Two, he proudly told his country: «If the territorial integrity of our country is threatened, we will, without doubt, use all available means to protect Russia and our people.

«This is not a bluff.”

Since then, Putin has stamped all over hard-fought nuclear arms treaties, including the last remaining bi-lateral pact with the US, and ramped up his threats that a nuclear strike is not only possible, but probable if Russia is threatened or better yet humiliated.

These threats have filtered down further into the population through milbloggers and Kremlin mouthpieces who have called for the use of nukes to smash “the will of the West».

In two weeks of June, a Nobel Prize-winning Russian journalist recorded 200 instances of Russian state TV declaring the use of nuclear weapons “was possible” and how exactly it was possible.

Dmitry Muratov, whose independent newspaper was forced out of Russia, said: “Two hundred times. In two weeks. It is beginning to look like a dog food ad.”

He asked: “Will Vladimir Putin press the button, will he not? None of us know.”

This month, the Russian leader moved nuclear warheads into neighbouring Belarus, edging the nuclear threat ever-closer to Nato’s borders.

It was a move that President Biden called «absolutely irresponsible».

An organisation not taking any of Putin’s threats as a “bluff” is the International Campaign to Abolish Nuclear Weapons (ICAN).

“We are taking it very seriously and condemn the escalation of nuclear use,” Alicia Sanders-Zakre, ICAN’s Policy and Research Coordinator, said.

She told The Sun: “Right now, the nuclear threat is higher than we have ever seen.

“It’s insane to say we have a stable security environment.

«This all depends on one individual having the power over all their nuclear arsenal. We cannot trust humans to act rationally.»

Former US ambassador to Ukraine John E. Herbst told The Sun that any escalation in the war would involve two disastrous — and irrational — options for Putin.

“One would involve mobilising more troops — which made many [Russians] unh

Since then, Putin has stamped all over hard-fought nuclear arms treaties, including the last remaining bi-lateral pact with the US, and ramped up his threats that a nuclear strike is not only possible, but probable if Russia is threatened or better yet humiliated.

These threats have filtered down further into the population through milbloggers and Kremlin mouthpieces who have called for the use of nukes to smash “the will of the West».

In two weeks of June, a Nobel Prize-winning Russian journalist recorded 200 instances of Russian state TV declaring the use of nuclear weapons “was possible” and how exactly it was possible.

Dmitry Muratov, whose independent newspaper was forced out of Russia, said: “Two hundred times. In two weeks. It is beginning to look like a dog food ad.”

He asked: “Will Vladimir Putin press the button, will he not? None of us know.”

This month, the Russian leader moved nuclear warheads into neighbouring Belarus, edging the nuclear threat ever-closer to Nato’s borders.

It was a move that President Biden called «absolutely irresponsible».

An organisation not taking any of Putin’s threats as a “bluff” is the International Campaign to Abolish Nuclear Weapons (ICAN).

“We are taking it very seriously and condemn the escalation of nuclear use,” Alicia Sanders-Zakre, ICAN’s Policy and Research Coordinator, said.

She told The Sun: “Right now, the nuclear threat is higher than we have ever seen.

“It’s insane to say we have a stable security environment.

«This all depends on one individual having the power over all their nuclear arsenal. We cannot trust humans to act rationally.»

“One would involve mobilising more troops — which made many [Russians] unhappy and Putin is very afraid of that — or for Putin to use tactical nuclear weapons in Ukraine,» he said.

«The latter is unlikely but you just can’t rule it out….it won’t stop the Ukraine fighting back, it will annoy his pals in China and India and it will force Biden to have to strike back.»

While Yavlinsky fears a full-blown “East to West” nuclear war, some military analysts are panicking over a seemingly nearer threat — the world’s largest nuclear power plant stationed within the Russian-controlled side of a warzone.

Ukrainian President Volodymyr Zelensky has repeatedly raised the alarm that Russia is plotting to unleash a radioactive leak from the plant, citing intelligence that Putin’s forces have “mined” the site.

“This time it should not be like Kakhovka,” he said, referring to his persistent claims that Russia intended to blow up the hydroelectric dam before it was destroyed on June 6.

“The world has been warned, so the world can and must act.”

To this, Yavlinsky said: “I want to stress, this is the situation in this war, this real war, anything can happen – the huge explosion at [Kakhova Dam] was a sign.

“Everything can happen. No limits. What will happen tomorrow, nobody knows.”

Chemical weapons expert Colonel Hamish de Bretton-Gordon shares these concerns.

As he watched the almost coup play out last weekend and Russia descend into chaos, “the nuclear threat was the biggest worry,” he told The Sun.

But with the rebellion called off, «an accident — whether deliberate or not — at Zaporizhzhia or another nuclear power station is still possible».

In a post-Wagner-revolt Russia, Kyiv is claiming the “countdown” has begun on the end to Putin’s rule.

Andriy Yermak, President Zelensky’s closest adviser said: «This is a terrorist country whose leader is an inadequate person who has lost connection with reality,» BBC reported.

«I think the countdown has started.»

Ex-Nato officer Samantha de Bendern sees Putin using nukes as «unlikely», but she told The Sun the «only way» would involve the fall of despot’s regime.

«If there was a power collapse in Russia, if tensions were to erupt and the state fell into chaos,» she said.

The Chatham House expert added: «It’s far-fetched, but if Putin is on the way out, he could decide to take us all with him.»

«I am against this war, against Putin’s so called ‘special military operation’…. but there will be no victory for either Russia or Ukraine, it’s a big tragedy.

“We need to make the first, but absolutely inevitable and crucial step of a ceasefire … to reach an understanding in major capitals which are playing the war in Moscow, Kyiv, Washington, Brussels.