The Labour leader met Alex Younger – the head of the UK’s intelligence service – at the organisation’s headquarters in Vauxhall, where Mr Corbyn was briefed on threats to Britain.
The move is a sign that a snap election could be imminent as the Prime Minister battles strong opposition to her Brexit proposals.
A source said to the Daily Telegraph: “The feeling was that the time had come for Mr Corbyn to become acquainted with the workings of the intelligence establishment.”
Mr Corbyn has repeatedly called for a snap election, with the left-wing leader confident his party would win.
But the Leader of the Opposition admitted that Brexit cannot be stopped.
Asked by German magazine Der Spiegel if he would stop Brexit if he could, Mr Corbyn said: “We can’t stop it.
“The referendum took place. Article 50 has been triggered. What we can do is recognise the reasons why people voted Leave.”
It comes after the resignation of transport minister Jo Johnson yesterday piled further pressure on Mrs May as she attempts to strike a Brexit deal with the EU.
Boris Johnson’s brother, who campaigned for Remain, called for a second referendum as he announced he was stepping down.
The Orpington MP said: “To present the nation with a choice between two deeply unattractive outcomes, vassalage and chaos, is a failure of British statecraft on a scale unseen since the Suez crisis.
“We are barrelling towards an incoherent Brexit that is going to leave us trapped in a subordinate relationship to the EU.
“With no say over the rules that will govern huge swathes of our economy.”
And Mrs May is under high pressure from the DUP over the issue of the Northern Ireland-only backstop.
DUP leader Arlene Foster warned her party would vote against Mrs May’s plans, in what is a huge blow to the Prime Minister who relies on the 10 DUP votes after losing her majority in the House of Commons after her 2017 snap general election.
Writing in the Daily Telegraph, Ms Foster said: “If what is outlined in the reply is the type of deal the Prime Minister intends to conclude, then the DUP could not support a deal which annexes Northern Ireland from the rest of the United Kingdom.
“The ‘new’ idea of a UK customs arrangement does not appear to be a genuinely UK-wide offer but a GB offer and an NI offer badged as one – Northern Ireland in THE EU customs territory and GB in A customs union.
“The real intent is not to solve any land border issues in Ireland but to handcuff the UK to the EU, with the EU holding the keys. The United Kingdom would be trapped.”