British factories manufacturing drones for Ukraine could face targeting by "unknown sources", a Kremlin adviser has warned, after the UK agreed to share long-range missile blueprints with the nation.Andrei Fedorov, a former deputy foreign minister for Russia, stated he could not "100% exclude" the possibility of "semi-military" operations directed at Britain, speaking as Andy Burnham undertook a trip to Kyiv.The visit marked the Prime Minister’s inaugural overseas journey since taking office. While in the capital, the UK reaffirmed its "unwavering" commitment to Ukraine, which in turn provided what officials described as a "goldmine" of combat data to enhance British security.In discussions with Ukrainian President Volodymyr Zelensky, Mr Burnham assured there would be "no change in the UK’s steadfast support" for the country.Mr Fedorov told BBC Newsnight that “sooner or later, there might be not only verbal, but maybe some visible reaction from Russia towards the UK”.Ukraine’s President Volodymyr Zelensky (right) welcomes and shakes hands with Prime Minister Andy Burnham upon his arrival at Horodetskyi House ahead of their bilateral meeting in Kyiv, Ukraine, during his first foreign trip, to mark Ukraine’s independence day and signal the UK’s continued support for the country under his administration. Picture date: Monday August 24, 2026. (PA Wire)Asked to elaborate, he said: “There are different discussions how it should look like – it might be so-called technical reaction, maybe some hackers attack from unknown source, not from official level of course.“There might be different political steps and I cannot exclude 100% that there might be some semi-military, for example.”Pressed to define “semi-military” he said: “For example, something might happen with enterprises, with the factories which are producing drones for Ukraine, etc etc.”Asked whether this meant British factories in Britain being attacked militarily by Russia, the adviser said: “They could be attacked, not by Russia, but by… from unknown sources.”The UK has agreed to declassify blueprints for British-made components for the Scalp missile, a French-produced version of the Storm Shadow that has already been used to hit targets in Russia.That decision has drawn strong condemnation from Russia, with President Vladimir Putin’s spokesman Dmitry Peskov saying it would add “fuel to the fire” of the conflict.But Mr Burnham told reporters in Kyiv: “Who started the fire? That’s the question, isn’t it?”During his visit, the Prime Minister urged Ukraine’s allies to send more interceptor missiles to Kyiv as Ukraine struggles under continued Russian bombardment.He co-chaired his first coalition of the willing meeting, where he said the group was doing “everything we can” to “dig into our own stocks and help others dig into their stocks”.Mr Zelensky has repeatedly pleaded for more US-made Patriot interceptor missiles in recent months as Kyiv’s stocks have diminished.Supplies of Patriots have been diverted to the Middle East since the outbreak of war with Iran, with Ukraine receiving significantly fewer missiles this year than in previous years.Russia has sought to capitalise on the shortage by stepping up its ballistic missile strikes, killing at least 23 people and wounding more than 100 in the past three days alone.Ukraine’s President Volodymyr Zelensky (right) with Prime Minister Andy Burnham (left)Mr Burnham stressed the “strength of unity” among coalition of the willing countries during his bilateral talks with Mr Zelensky, Downing Street said.A No 10 spokeswoman said: “It had been an honest and productive conversation during the coalition of the willing, the leaders agreed, and it was clear the international community needed to step up and ensure Ukraine got the support it needed to defend itself from Russia’s barbaric attacks going into the winter.“The Prime Minister emphasised the strength of unity among coalition members and reiterated that there would be no change in the UK’s steadfast support.“That was further symbolised by the announcement that the UK had agreed that defence firm MBDA could release classified information on UK components for the long-range missile, Scalp, the Prime Minister said.”Andy Burnham plays the guitar in the mobile recording studio of the military and artistic unit who perform on the front line, in hospitals and at rehabilitation centres (Henry Nicholls/PA Wire/PA Images),During his visit Mr Burnham played Rusholme Ruffians by The Smiths after being handed a guitar by a Ukrainian soldier, a moment he later shared on social media.The Prime Minister, who explained it was a Manchester band and strummed a few chords but declined to sing, said music can help “lift spirits” on the front line. Soldiers sang him an Oasis song.He later went to a shopping centre that was destroyed in a Russian attack, where he mingled and took selfies with residents.Mr Burnham and Mr Zelensky have also signed an agreement to give the Ministry of Defence, working with selected British companies, access to Ukraine’s “Avengers” AI database, Downing Street said.The deal is expected to help the UK learn from Ukraine’s experience on the battlefield and develop AI-powered solutions to national security challenges in both countries.