Britain's main opposition Labour Party will promise to renationalise rail and mail services and take some of the energy sector into public hands in a shift to the left aimed at winning over voters before next month's election.
In an impassioned speech at Chatham House in London, Mr Corbyn said he isn't a pacifist, but cautioned against military action overseas.
Asked whether parliamentary approval would be sought first, Mr Johnson replied: "It is a hypothetical question and as I said then and I say now we would have to decide. I accept that military action, under worldwide law and as a genuine last resort, is in some circumstances necessary" - from Mr Corbyn's speech to be given at Chatham House.
Some recent opinion polls have put Prime Minister Theresa May's Conservatives ahead of Labour by more than 20 percentage points and on course for a landslide victory.
The PM also sounded somewhat reticent about the same foreign entanglements in the very Philadelphia speech that Mr Corbyn criticised.
A senior party source was forced to clarify Mr Corbyn's remarks and reiterate that Labour policy was to renew the four missile submarines that carry Trident nuclear weapons, as voted by MPs past year.
Mr Corbyn is expected to reject criticism over his position on defence and the use of nuclear weapons by insisting: "I am not a pacifist".More news: Atletico Madrid defender Theo Hernandez passes medical with Real Madrid
Mr Corbyn said a government under his leadership would have "a "robust and independent foreign policy". They have not increased our security at home - just the opposite, and they have caused destabilisation and devastation overseas", he said.
But there can be no doubt that security is a big perceived weakness among the electorate for Labour under Mr Corbyn. "But that is very far from the kind of unilateral wars and interventions that have nearly become routine in recent times".
Corbyn, a longtime anti-war activist who opposed the invasions of Afghanistan and Iraq, used a speech at the global affairs think tank Chatham House to outline his vision for defense and foreign policy.
The Labour leader said that the terms of Article 5 of the Nato treaty, which commits member-states to collective self defence, could in some circumstances be fulfilled without the use of military force, by deploying economic and diplomatic pressure. "It would mean world leaders had already triggered a spiral of catastrophe for humankind".
The Conservatives said they want to find a way children can erase embarrassing content, without losing their existing social media account and the online connections they have made.
"We all want peace, but you can't take tea with terrorists who order attacks on innocent civilians on our streets".