Britain is to hold its largest defence exercise in decades in 2027.
Dubbed "Operation Albiston Shadow", the Cabinet Office said the scenario will likely involve ministers as well as hundreds of officials from across government and the public sector.
It will test responses to "hybrid" attacks under the threshold of conventional war.
Tensions mount between Britain and Russia as Russia continues to attack Britain's ally Ukraine.
Dubbed "Operation Albiston Shadow", the Cabinet Office said the scenario will likely involve ministers as well as hundreds of officials from across government and the public sector.
It will test responses to "hybrid" attacks under the threshold of conventional war.
Tensions mount between Britain and Russia as Russia continues to attack Britain's ally Ukraine.
