David Cameron has labelled the Labour Party "a threat to national security" now that Jeremy Corbyn has been elected as leader.
As Corbyn is set to announce his shadow cabinet, the Prime Minister tweeted: "The Labour Party is now a threat to our national security, our economic security and your family's security."
Corbyn on Saturday scored an overwhelming victory in the Labour leadership race, winning almost 60% of the vote.
Before the veteran MP's win was announced, Cameron warned that Corbyn would break a valuable consensus between the main parties on issues such as nationalisation, nuclear weapons, taxation and union laws.
He said: "The country is stronger when you have shared objectives rather than when you've got someone who wants to take us back to the days of Michael Foot and Arthur Scargill."
Corbyn on Saturday declared that his ‘enormous mandate’ means he will fight the next general election no matter what setbacks he faces in the next five years.
Corbyn vowed to remain in post to 2020 and signalled that Labour MPs had to accept the will of more than quarter of a million party members.
Despite a planned walk-out by shadow ministers who felt his views were too left-wing to serve under him, Corbyn played down any disunity by stressing he had plenty of colleagues asking to join his team.