Super Tuesday: Mystery dark money group spends almost $1m on anti-Bernie Sanders ads across 10 states

‘Why are they funding these ads? Because we have a corrupt political system’

Almost $1m has been spent on political adverts attacking Bernie Sanders by a group not legally required to reveal its donors, it has been reported.

In a development that will be of intense concern to the 78-year-old Vermont senator and his supporters, it was reported that the so-called political action committee Big Tent Project Fund, had spent $868,000 on digital ads.

This follows previous expenditures on adverts attacking the progressive former mayor of Burlington.

The group had previously spent almost $5m in adverts attacking the senator during the caucus in Nevada and the primary in South Carolina. Politico said the the nonprofit organisation — commonly known as a dark money group because it is not legally required to disclose its donors — said in a filing with the Federal Election Commission on Tuesday that it spent just the money in 10 states, all of which were voting today on Super Tuesday.

“Now who is funding these ads? Why are they funding these ads? Well, because we have a corrupt political system,” Mr Sanders said about the group at a news conference on Monday.

The group is helmed by Jonathan Kott, a former senior aide to West Virginia senator Joe Manchin.

“Socialist Bernie Sanders is promising the world, but at what cost? 60 trillion dollars in spending and the largest middle class tax hike ever. So what’s the true cost? 4 more years of Trump,” reads one of the ads from the group currently running on Facebook.

As moderates in the party move to consolidate his campaign so Mr Sanders has claimed “the establishment is getting scared”.

He often tells supporters they will have to confront the “Democratic political establishment” if the are to win.