Mason – a vocal supporter of Labour’s second referendum Brexit policy, which many party members blame for PM Boris Johnson’s landslide victory in December – hit out at those planning to vote for Rebecca Long-Bailey as Jeremy Corbyn’s successor.

The former BBC and Channel 4 News journalist took to Twitter on Monday as voting for a new Labour leader got under way. He urged Labour members to vote for pro-EU, center-left candidate Keir Starmer, calling it a “no-brainer” of a choice and branding those opting for Long-Bailey – the democratic socialist candidate – as “Stalinists.”

Mason’s swipe at members opposed to Starmer – the supposed ‘unity’ candidate –provoked anger from many Labour supporters on Twitter. Many of those who took a pop at Mason saw his comments as anything but ‘unifying.’

He also received a backlash for blaming certain Long-Bailey supporters for having “destroyed Corbynism,” with some taking aim at him over pushing for a ‘people’s vote’ or second referendum on Brexit. One person tweeted: “Who are the Stalinists? It was the People's Vote fanatics like you that destroyed Corbyn.”

Others ridiculed his somewhat over-the-top characterization of those who had the temerity to disagree with him, with the irony not being lost on some of his critics. One Labour supporter sarcastically tweeted that he should learn the true meaning of ‘Stalinist’, adding: “The clue is, it's not someone disagreeing with you or being left of you... I mean, the Teletubbies are left of you right now.”

Gifs were also posted mocking his assertions, with some left feeling slightly bemused as to why voting for a democratic socialist candidate could trigger such histrionics from Mason.

Starmer, Long-Bailey and Lisa Nandy are all hoping to become the next Labour leader when ballots close on April 2, with the winner due to be announced on April 4. The successful candidate will then be given the unenviable task of leading the party into the next general election – scheduled for 2024 – having seen the Labour Party lose the last four.