Amid Democratic mourning over the loss of the presidential election to Donald Trump, the party chair risked deepening already growing divisions by rebuking the leftwing Vermont senator Bernie Sanders for saying Democrats have “abandoned working class people”.

“This is straight up BS,” Jaime Harrison, the Democratic National Committee chair, said on Thursday. “[Joe] Biden was the most pro-worker president of my lifetime – saved union pensions, created millions of good paying jobs and even marched in a picket line.”

Harrison also defended Kamala Harris, the vice-president who lost the election to Trump, for proposing policies that “would have fundamentally transformed the quality of life and closed the racial wealth gap for working people across this country”.

He said: “From the child tax credits, to [$]25k for a down payment for a house to Medicare covering the cost of senior healthcare in their homes. There are a lot of post-election takes and this one ain’t a good one.”