A motion overwhelmingly carried at the Bakers, Food and Allied Workers Union conference said fat cats “should be tried in court and imprisoned if found guilty” should the banking system collapse again.

Bristol delegate Adam Brown said: “Those who caused this should face the maximum penalty.”

The conference resolved to lobby for new laws to criminalise abusive practices if necessary, “to stop the fraud that happens on a regular basis.”

The union also called for the government to “penalise” banks that move offices abroad after Britain leaves the EU.

Wakefield delegate John Lloyd said: “The point is this, they’ve got to take some blame for financial meltdown.”

Another delegate, Steve Day, said: “We need to go further than this.

“I think we need to follow Iceland and we need to jail the lot of them.”