The UK is “on guard”, the defence secretary has said, after concerns were raised that Russia could use chemical weapons if Ukraine’s counter-offensive is successful in regaining territory.

Tobias Ellwood, the Conservative MP who chairs the Commons Defence Committee, asked Ben Wallace if he was concerned that Vladimir Putin will “turn ugly and resort to non-conventional weapons systems... as he did in Syria.”

“We are on our guard, the international community regularly communicate, we stand ready with Nato, we increase our readiness as we do, and we have started to increase the investment in our capabilities,” Mr Wallace said.