Russia has threatened to target British factories in a "semi-military" response to the United Kingdom's support for Ukraine, with President Vladimir Putin warning that "Pandora's box has been opened." The Kremlin's rhetoric escalated after a UK official announced that European defense firm MBDA had received permission to share information on UK components for the long-range SCALP missile.

A senior Russian advisor, identified as former Deputy Foreign Minister Andrei Fedorov, stated that Moscow views the UK as "evil number one" and that the recent announcement from Prime Minister Andy Burnham, who was visiting Kyiv, had elicited a "very negative" reaction from the Kremlin. Fedorov suggested that political and public pressure on President Putin necessitates measures against the UK, which is considered a participant in the war in Ukraine.

Fedorov indicated that a new stage of escalation could involve a "not only verbal but maybe some visible reaction" from Russia. This could manifest as "technical reaction, maybe some hackers attack from unknown source, not from official level," or potentially "some semi-military" actions. He clarified that British factories producing drones or components for Storm Shadow missiles could be targeted by "unknown sources."

Kremlin spokesperson Dmitry Peskov reiterated on Monday that "Britain is participating in this war" and accused the UK of "methodically and regularly pour[ing] fuel on the fire" and preventing peace progress. He added that Russian armed forces intended to identify and destroy "production sites of such missiles, the production sites of other military equipment."

Despite the threats, Prime Minister Burnham insisted that the UK's support for Ukraine would not waver, calling Russia's threats "outrageous." He questioned Russia's role in initiating the conflict and reaffirmed the UK's commitment to Ukraine's defense. Burnham emphasized that the UK would "not back down until there is a lasting peace."

The UK's decision to share information on SCALP missile components means the weapons, which are built using both British and French technology, could now be produced locally in Ukraine. These missiles are considered critical for long-range strikes into Russian-held territory.

Burnham also chaired a meeting of the "coalition of the willing," urging allies to provide Ukraine with more Patriot interceptor missiles and to increase economic pressure on Russia. He noted that Russia's economy is reportedly facing challenges, including a significant budget deficit and declining oil revenues.

Relations between Russia and the UK have reportedly reached "an unprecedentedly low level," with Russia withdrawing its ambassador from London after seven years. The Russian ambassador had previously accused the UK of choosing "a path of confrontation" with Russia.