Ukraine is racing to finish multiple lines of defence that could halt Russia’s swift advances, but efforts have so far been marred by delays and lack of co-ordination, according to Ukrainian officials and commanders.

Russian troops have been making the swiftest gains in the eastern Donetsk region this year, pushing the frontline west, in some places to as close as 15km from the border with neighbouring Dnipropetrovsk region. If Vladimir Putin’s soldiers crossed that line, it would mark the first breach into a new Ukrainian region since 2022 and deal a significant blow to Kyiv’s war effort.

“The situation with fortifications is another factor demoralising troops,” said Dmytro Razumkov, a former ally of President Volodymyr Zelenskyy who is now on the parliamentary committee investigating delays and alleged corruption in the effort to build defences.