Britain has urged a reluctant Berlin to supply long-range Taurus missiles to Kyiv despite an embarrassing leak to Russian television of a top-secret call involving German air force officers who said UK troops were “on the ground” in Ukraine.

Released by the editor of the Kremlin-controlled news channel RT, Margarita Simonyan, the audio recording – confirmed as authentic by Germany – captures Luftwaffe officers discussing what they said was Britain’s military presence in Ukraine, helping the country select Russian targets.

Rather than publicly criticise Germany over the leak, Britain said it was for Berlin to investigate. Instead the UK toughened up its own lobbying on the Taurus missiles, which have a 300-mile range, twice that of Anglo-French Storm Shadow/Scalp weapons system already given to Kyiv.

“The UK was the first country to provide long-range precision strike missiles to Ukraine, and we would encourage our allies to do the same,” a Downing Street spokesperson said. “The presence of a small number of British troops in Ukraine” had been acknowledged by No 10 a week earlier, they added.

Former Ministry of Defence insiders added they believed the leak was irritating but not significant, partly because the conversation was not very specific – and that, on the plus side, it also emphasised how effective Taurus could be.

Scholz insisted he would not change his mind about Taurus, as he met a group of voters at a vocational school in Baden-Württemberg and cited concerns Ukraine could use the weapons to strike at the heart of Russia. “I am the chancellor and my word counts,” he said.

Control over the Taurus missiles, theoretically able to hit targets in Moscow, would only be guaranteed if German soldiers were directly involved in firing them, and “that is completely out of the question”, Scholz added.

Downing Street had confirmed the presence of a “small number of personnel” in Ukraine last week, although it did not spell out all tasks they were undertaking due to concerns that any potential combat involvement could be considered as escalatory by Moscow.

There were signs of German divisions after the leak. Annalena Baerbock, the foreign minister, from the governing coalition’s junior partner, the Greens, reiterated her support in principle for giving Taurus missiles to Ukraine.