OLEKSANDR DAVYDKO’S usual instrument of choice is his plumber’s wrench. Now he grips his Kalashnikov automatic rifle as he and his comrades run through a maze of obstacles on a mock battleground.

Davydko, 28, and fellow recruits to Ukraine’s newly formed national guard fear they could face shots on a real battlefield if Russia follows its annexation of Crimea by launching an assault on the Ukrainian mainland.

Sergei Lavrov, the Russian foreign minister, insisted yesterday the Kremlin had no intention of sending its forces into the country.

He was speaking after Vladimir Putin, Russia’s president, called his American counterpart, Barack Obama, to discuss a possible diplomatic solution to the crisis. Lavrov and John Kerry, the US secretary of state, are due to meet in Paris