Jeremy Corbyn has suggested that a Labour government may consider scrapping Britain's Trident nuclear deterrent.
"We will have a strategic defence review immediately which will include all aspects of defence", he told the Andrew Marr show. "He enabled it. It has put us in the situation we are now in".
Asked whether supporting Trident renewal would be in Labour's manifesto Mr Corbyn replied: "We haven't completed work on the manifesto yet".
Having repeatedly denied that she would call an election, May is now also poised to announce a raft of policy proposals more commonly associated with the left-leaning Labor party, according to the Sunday Times.
He described Theresa May as "very sensible" and "a perfectly decent person" but said her policy on leaving the European Union was "not reasonable" and that it was driven by the right wing of her party.
He pledged Labour would keep Scotland in the United Kingdom and ensure the whole country is "a far fairer, a more just and equal version of anything the Tories could ever offer".
"Let me be clear - there will be no deals with the SNP or anybody else".
Jeremy Corbyn spoke at a festival today to mark 40 years since National Front members marched through Wood Green, London.
"I think the leader of Isis not being around would be helpful".
"At this election people are going to have a very clear choice, between a Conservative Party which always has been, is and will continue to be a party that believes in lower taxes", she said.
Speaking ahead of the three-day congress, STUC general secretary Grahame Smith demanded Prime Minister Theresa May hand Holyrood new powers on immigration and employment rights post-Brexit.
"The dividing lines in this election could not be clearer from the outset - it is the Conservative Party, the party of privilege and the richest, versus the Labour Party, the party that is standing up for working people to improve the lives of all".
In his interview, Mr Corbyn suggested he could suspend RAF air strikes on IS in Syria and Iraq, and said he would urge US President Donald Trump to resume worldwide peace talks on Syria in Geneva.
Meanwhile, Corbyn declared on Sunday that he could suspend British involvement in air strikes against Syria if he was elected prime minister in June. "Possibly. The point has to be to bring about a political solution".
He insisted: "Labour will negotiate a Brexit that will build on the gains won for workers, consumers and the environment in the European Union".
This being said, it is impossible to negate the whiff of opportunism when it comes May's decision to go for an early election.
His comments were pounced upon by the Conservatives, who said that Corbyn posed a threat to British security and was the best reason "for sticking with the strong leadership of (Prime Minister) Theresa May".