Liberal Democrat leader Tim Farron told the Press Association: "It doesn't matter whether it was leaked or not leaked, the Labour manifesto ceased to be relevant in any way, shape or form the moment Jeremy Corbyn and his party held hands with Ukip and Theresa May and voted for the triggering of Article 50".
Mr Corbyn denied he was a "pacifist" and vowed that his first duty, if Prime Minister, would be to do "everything necessary to protect the safety and security of our people and our country".
The Sun summed up the leak and following drama with the headline "Crash, Bang, Wallies!", The Times and Telegraph report "civil war" breaking out in the party over the "hard-left" manifesto, and the Daily Mail asks: "Who DID leak that manifesto?"
The 43-page document also says Labour will ensure that 60 percent of the UK's energy comes from renewable sources by 2030, the newspaper added.
A senior Labour source said suggestions the manifesto was leaked by Mr Corbyn's team were "categorically and completely untrue".
Roughly a quarter of people (22, 24 and 25 per cent respectively) said they opposed the policies, outlined in the party's draft document, which was signed off by Labour executives at a meeting on Thursday.
Reuters could not confirm or deny the details in the report.
Corbyn said that a Labour government would seek greater global cooperation to end the conflict in Syria and "work to halt the drift to confrontation with Russia. winding down tensions on the Russia-NATO border".
Argentina got mistaken for Australia and a BBC cameraman ended up in an ambulance when his foot got run over by Jeremy Corbyn's auto - here are some of the key moments from Thursday's General Election campaign. But the big question is, what do Labour want to transform Britain into?
What have the Conservatives said?
Jeremy Corbyn will say he accepts that military action is needed as a "last resort" but that Labour wants independent foreign policy and "no hand holding" with US President Donald Trump.
Britain's military interventions in Syria, Afghanistan, Libya and Afghanistan have made the country less safe, Jeremy Corbyn argued today.
Despite Mr Corbyn's declaration that the Brexit question was "settled" by last year's referendum, the document states withdrawing from the European Union without a deal would be the "worst possible" outcome and would be rejected as a "viable" option.
"Jeremy Corbyn's plans to unleash chaos on Britain have been revealed".
However, the Labour leader and former chairman of the Stop The War Coalition has clashed with his own party, including shadow defence secretary Nia Griffith, over his opposition to Britain's nuclear deterrent.
Mrs May, for her part, has promised to spend more on defense, announcing that a Conservative government would meet its North Atlantic Treaty Organisation spending target but would also increase the military budget "by at least 0.5 per cent above inflation in every year".