Vladimir Putin intends to cause the UK harm and it is “time to be serious” about threats facing Britain, a former military chief has warned.

Stuart Peach, former chief of the defence staff, said Russia poses “a threat to our way of life”, amid increasing concern that the UK’s undersea cables – which are vital to internet access, financial transactions and the sharing of essential data – are vulnerable to sabotage.

But he warned that Britain was not prepared to deal with potential threats to the nation, such as widespread power cuts and full-scale war.

He said: “The fact that Russia intends us harm – whether it’s economic disruption or the ‘dark arts’, as you might call them – I think the evidence is clear.”

His warning came in a joint interview with The Independent alongside the chair of the House of Lords National Resilience Committee, Jean Coussins.

The two crossbench peers, who are not politically aligned, highlighted the need for a sense of “urgency” when it comes to Britain preparing for potential threats.

“How many of us are prepared with enough bottled water, tinned food, batteries and medication to last for a couple of weeks – or more – if there was a national power cut, or no running water, no petrol to drive to the shops, where the shelves are empty of food anyway? No wifi, no internet, no working cash machines?” Baroness Coussins asked.

She also warned that Britain was already under attack.

“It is not a question of ‘what if?’ It’s a question of ‘these things are happening now’,” she said.

“We know we’re under cyber attack daily. We know that there are proxy attacks on the part of Russia, Iran and so on.

“We know from what MI5 tells us publicly how many incidents of potential violence they are stepping in, identifying and preventing.”

The head of the GCHQ recently warned that Russia is “relentlessly” targeting critical infrastructure, democratic processes, supply chains and public trust in the UK and Europe.

Read More: We must take threat from Russia seriously, ex-military chief warns UK