Hamish de Bretton-Gordon, a former British tank commander, said Storm Shadow missiles would be able to strike “rail heads and key roads coming into Kursk, plus any airfields within 100 miles”.

“Putin is rattled and this would show the West is fully committed to Ukraine, which has not been apparent hitherto,” he added.

The position on how Storm Shadow missiles are used is not just the UK Government’s to make, since the missile is manufactured with France, meaning Paris also has a say on conditions.

Kyiv has also asked Washington for permission to use its Atacms long-range missile during the Kursk offensive, but that has so far also been refused.

Putin appeared frustrated as he addressed his top brass in a publicly broadcast meeting in the Kremlin.

“The West is fighting us with the hands of Ukrainians,” he told officials including Valery Gerasimov, Russia’s top general, Viktor Zolotov, the head of Russia’s National Guard, and Alexander Bortnikov, the head of the FSB security services.

“Apparently, the enemy is striving to improve its negotiating positions in the future. But what kind of negotiations? How do we even talk with people who indiscriminately strike at civilians, at civilian infrastructure and try to create threats to nuclear energy? What can we even talk about with them?” he said.