Putin's grip on power may be weakened by 'colossal error' in Ukraine

Russian President Vladimir Putin is beginning to understand the "colossal mistake" he has made in invading Ukraine, western officials believe, amid signs his grip on power may have been weakened.

The Kremlin is expected to move swiftly to annex four territories occupied by his forces in the east of the country after conducting a series of "sham" referendums on joining the Russian Federation.

The move was denounced by western officials as a "panic" measure after reverses suffered by Russian forces in a Ukrainian counter-offensive in the north of the country.

Officials report growing opposition to the Russian leader after his announcement last week of a partial mobilisation of military reservists, with an estimated 250,000 men having left the country to avoid the draft.

The exodus comes on top of 400,000 thought to have left in the immediate aftermath of the invasion in February, including many of the country's best-educated and most skilled workers, adding to the pressure on a Russian economy already hit hard by sanctions.

Protests against the mobilisation are also reported to be increasing, with western officials saying they tracked 17 fires started at recruitment centres in the four days after the call-up.

One official said it is becoming increasing clear to the Russian people that their country has suffered a humiliation which could ultimately weaken Mr Putin's grip on power.

"The mobilisation announcement means that more and more Russians are coming to understand that they are being lied to," the official said.

"The elites know this is not going to plan. It is pretty clear that there is a lot of blame being thrown around. We have seen on state media comments about Putin being misled by senior military," the official said.

"I am not predicting we will see any imminent change. If you had asked me a year ago I thought we had this current team in power probably into the 2030s. I think that is much less clear now.

"This is such a huge mistake. Many people understand now Russia has been humbled by this colossal error. That will have consequences but I think it will play out over quite a number of months, if not years."

Western officials said Mr Putin needed to dial down his "deeply irresponsible" threats after he warned any attack on Russian territory could be met with a nuclear response.

His words were interpreted as a warning to Ukraine not to try to retake the territories of Donetsk, Luhansk, Kherson and Zaporizhzhia if, as expected, they are incorporated into Russia.

"Russia is a permanent member of the United Nations Security Council. It is completely outrageous and deeply irresponsible for this sort of language to be used. They need to de-escalate," one official said.

Officials also said there needed to be proper investigation into a series of explosions which hit Russia's undersea Nord Stream 1 and 2 gas pipelines amid suspicion they were deliberate sabotage by Moscow to exacerbate the energy crisis in the West.

"It is going to have to be investigated seriously, thoroughly and properly. It is a very serious development," one official said.

"There were a number of explosions. It looks highly suspicious but I think we need to establish the facts and then attribute."