Democratic presidential candidate accuses Super Pac associated with Hillary Clinton of crude slur after it reportedly criticised his support for Jeremy Corbyn

An uneasy truce between Democratic presidential frontrunners Hillary Clinton and Bernie Sanders broke down on Tuesday as the Vermont senator accused a group associated with the former secretary of state of a “vicious” attack on his support for new British Labour party leader Jeremy Corbyn.

In a war of words that heralds a new phase in the hitherto relatively polite Democratic primary campaign, Sanders was reportedly criticised over his backing of Corbyn – the leftwing socialist who came from nowhere to win a landslide victory in the Labour leadership contest on Saturday – by Correct the Record, a so-called Super Pac that raises unlimited sums from wealthy donors to support Clinton.

According to journalists who received an email from the group, it attacked Sanders for congratulating Corbyn on winning the Labour leadership election and drew attention to the British politician’s “most extreme comments” on foreign policy.

Many of the alleged comments, such as remarks referring to Hamas and Hezbollah as “friends” and the death of Osama bin Laden as a “tragedy” are similar to attacks on Corbyn from rightwing critics in Britain that his supporters say are based on distortions of his positions.

The email also reportedly compared Corbyn’s support for the late Venezuelan president Hugo Chávez with a decision by Sanders to help negotiate the purchase of discounted heating oil from the Latin American country for a number of US states.

Sanders has spoken little about his foreign policy during the campaign but responded angrily to the attack on Tuesday, suggesting it was a crude slur more worthy of Republican opponents than a fellow Democrat.



“Yesterday, one of Hillary Clinton’s most prominent Super PACs attacked our campaign pretty viciously,” said the senator in a statement sent to supporters. “They suggested I’d be friendly with Middle East terrorist organizations, and even tried to link me to a dead communist dictator.

Facebook Twitter Pinterest Labour party leader Jeremy Corbyn in Brighton, England, on Tuesday. Photograph: Mary Turner/Getty Images

“It was the kind of onslaught I expected to see from [Republican donors] the Koch Brothers or Sheldon Adelson,” he added.

Sanders has pulled ahead of Clinton in opinion polls for early states in the Democratic primary and his campaign believes it has also been targeted by the group before for appearing on stage with outspoken black academic Cornel West.

“It’s the second time a billionaire Super PAC has tried to stop the momentum of the political revolution we’re building together,” added Sanders in his letter to supporters, which sought small campaign donations to combat the influence of big donors on the presidential election.

Direct contributions to candidates are limited to $2,700 per election but Super Pacs are unlimited so long as their activities are seen as independent from the candidate they support. Correct the Record is one of two hybrid groups associated with Clinton that are able to make direct contributions and independent expenditure so long as separate bank accounts are used. It has already raised $1.4m from wealthy donors.

Neither Correct the Record nor the Clinton campaign responded to requests for comment on the alleged attack on the Vermont senator, who has featured little in the former first lady’s speeches, especially compared with the bitter infighting the Republican primary has seen so far.

Sanders campaign insiders say they have no desire to escalate any tension with Clinton but felt it necessary to respond to the attack when questioned on it by journalists.

Nevertheless the comparison with Corbyn could raise problems in future for Sanders, who is generally less radical than his leftwing British counterpart, particularly on foreign policy, and is seeking to find out more about his positions.

“At a time of mass income and wealth inequality throughout the world, I am delighted to see that the British Labour party has elected Jeremy Corbyn as its new leader,” Sanders said in an initial statement on Monday.

“We need leadership in every country in the world which tells the billionaire class that they cannot have it all. We need economies that work for working families, not just the people on top.”