A source familiar with the matter told Reuters on Wednesday that ground forces commander Oleksandr Syrskyi had been offered Zaluzhnyi’s job but turned it down.

The Ukrainian General Staff and president’s office did not immediately respond to requests for comment on the approach to Syrskyi.

Ukrainian forces are currently struggling in the battlefield.

A much-anticipated summer counteroffensive made little headway in the south and east, and Russian forces are inflicting small but costly defeats along the 1,000km front.

Western military and financial support is increasingly hard to come by, leaving Kyiv more exposed to regular attacks by Russian drones and missiles that are sapping its energy.

The state of the war is not down to Zaluzhnyi alone, but given his popularity and proven ability as an inspiring commander, the fact that Kyiv may be seeking to replace him may reflect the desire for a fresh approach to the war.

Defying overwhelming odds, Ukraine’s soldiers used stealth and speed to thwart Russia’s advance on Kyiv, helping to ensure that, even now, Russian President Vladimir Putin remains a long way from conquering Ukraine.

As the war progressed, Zaluzhnyi’s stock only rose, and he won praise at home and abroad when his forces launched major counteroffensives in the northeast and south that recaptured huge swathes of land and raised hopes of an unlikely victory.

A portrait of him smiling and flashing the peace sign was spray-painted on walls after the liberation of the southern city of Kherson, under the slogan “God and Zaluzhnyi are with us”.

Since then, Ukraine’s battlefield momentum has stalled, yet polling indicated that Zaluzhnyi was still trusted by 92 per cent of Ukrainians late last year, significantly above Zelensky’s 77 per cent.

Reported frictions burst into the open in November after Zaluzhnyi was quoted by the Economist as saying the war as at a “stalemate”, in a gloomy assessment that jarred with Zelensky’s more optimistic vision.

The 50-year-old four-star general, who rarely speaks in public but is occasionally shown on news bulletins poring over maps and addressing commanders in fatigues, argued that better technology is the key to breaking the impasse.

The president’s office rebuked him, and one of Zaluzhnyi’s senior officers said he had been sacked by Zelensky over the general’s head.

Were he to be removed and go into politics – though he has never voiced political ambitions – the “Iron General” could prove a formidable rival to anyone.

Zaluzhnyi began his military training in the 1990s, after Ukraine gained independence from the Soviet Union, graduating with honours and rising up the ranks.

He got a taste of real conflict in 2014 when he served in an area of eastern Ukraine where Russian-backed militants had seized territory.

Tall and burly with cropped hair, Zaluzhnyi, whose military call sign is “Volunteer”, has a reputation for having a good rapport with his subordinates and allowing local commanders to make their own decisions on the battlefield.

To many, he felt like a breath of fresh air among Ukraine’s older Soviet-style generals, and embodied Kyiv’s desire to break with the Soviet military practices it had inherited.

His warning in November that the war was sliding into an attritional phase that suited Russia was out of kilter with Kyiv’s official rhetoric, but for many of his soldiers it was recognition of the painful reality on the battlefield.

Putin’s spokesman, Dmitry Peskov, told reporters that the Kremlin is “of course” following the news about Zaluzhnyi.

“There are still many questions,” Peskov said, according to Tass, adding: “One thing remains obvious: the Kyiv regime has many problems, everything is wrong there. This is clear”.

“It’s obvious that the failed counteroffensive and the problems at the front have led to growing conflict … both in the military and civilian elite” in Kyiv, Peskov said. He predicted that “these conflicts will grow” as Russia’s military operation “continues successfully”.

Russia had been building up fortifications since late 2022 after suffering humiliating defeats in Kharkiv and Kherson regions, with more recent Ukrainian advances thwarted.

Tens of thousands of soldiers have been killed and wounded on both sides, although there are no reliable official figures.

Ukraine desperately needs to replenish its overstretched and exhausted ranks, but the government has been unable to amend call-up laws to help recruit up to half a million more soldiers.

Kyiv is also struggling to maintain Western support that has been vital to its war effort. Both the United States and the European Union have in the last two months failed to deliver hefty aid packages that they had promised.

It all means that, as deadliest conflict in Europe since World War Two enters its third year, Zaluzhnyi’s boots would be very hard to fill.

Additional reporting by Associated Press