Russia has accused Britain of being behind Ukraine's remarkable 'mini-invasion' that has stunned Vladimir Putin.

Thousands of Ukrainian soldiers charged across the Russian border this week for the first time since the conflict began. Since then, these troops have reinforced their positions, suggesting Ukraine intends to hold the territory it has seized.

The move – described last night by a former UK intelligence officer as a 'masterstroke' – could prove a game-changer in future peace talks.