BRITAIN planned to plant a nuclear bomb inside the Channel Tunnel to blow up the transport link in a desperate bid to severe ties with Europe.
Previously top secret papers have revealed that officials once plotted the collapse of the tunnel between the UK and France in the event of an emergency.
But they have resurfaced more than 50 years later, after being discovered tucked away in the National Archives at Kew.
And the cost was set to be astronomical if officials chose to carry out the secret plans.
The government would also be forced to keep the plot a secret from France, according to a letter from the Ministry of Defence that advised that explosive demolition ideas “should be covert and classified not less than SECRET UK EYES ONLY”.
The revelations come amid concerns of a looming European war following the triggering of Article 50 last week.
Now the future of Gibraltar hangs in the balance after the European Union appeared to back Spain in its long dispute with the UK over the territory.
Kent would suffer a certain amount of “collateral damage” if the blast went ahead
He said: “35 years ago this week another woman Prime Minister sent a task force half way across the World to defend the freedom of another small group of British people against another Spanish-speaking country.
“I am absolutely certain our current Prime Minister will show the same resolve in standing by the people of Gibraltar.”
Sir Michael Fallon, the Defence Secretary, has also pledged to “protect” Gibraltar on the Andrew Marr Show.