Moscow is seeking to undermine the UK's power by using cyber attacks and fake news, and Prime Minister Theresa May is set to hold a National Security Council meeting to assess the Russian aggression and how to respond, according to The Times.
It is thought that she will come to a decision about what to do within weeks.
In a meeting at the Cabinet office two months ago, intelligence officers and civil servants highlighted the scale of the threat from Moscow.
A source at the meeting said:
There was an agreement on the need to do more across Whitehall to understand and assess and formulate options on how to respond to Russian activities.
Britain is not the only target, as the Russians have been trying a number of avenues to destabilise the West.
He said: “We don’t have the evidence for that yet – but it is highly probable.”
The Russian Embassy responded to the accusations with a tweet:
President Barack Obama responded to the revelations, saying: "We need to take action and we will at a time and place of our own choosing."