Former US secretary of state Hillary Clinton on Monday launched a scathing attack on a presidential hopeful and 2016 Democratic rival Bernie Sanders, telling a documentary that “nobody likes him.”

Clinton also refused to say whether she would endorse and campaign for Sanders if he becomes the Democrats’ choice to take on President Donald Trump in November’s election.

Clinton further said, “Nobody likes him, nobody wants to work with him, he got nothing done. He was a career politician”.

Sanders, a leftist senator from Vermont, is among the leaders in the race for the 2020 Democratic nomination.

He sits second in national polls behind centrist Joe Biden and ahead of Massachusetts senator Elizabeth Warren, two weeks before the first nomination vote in Iowa.

Sanders, 78, pushed Clinton to the wire four years ago in an acrimonious, months-long battle for the party’s nomination. Clinton won that race but lost to Trump in November.

Warren has accused Sanders of telling her privately in December 2018, as they contemplated White House runs, that he did not believe a woman could win a presidential election.

Sanders denies the claim but Clinton said the comment was “part of a pattern.”

“If it were a one-off, you might say, ‘OK, fine.’ But he said I was unqualified,” she recalled.

“It’s the culture around him. It’s his leadership team. It’s his prominent supporters. It’s his online Bernie Bros and their relentless attacks on lots of his competitors, particularly the women,” she added.

Last year, in October, Sanders suffered a heart attack three days ago as doctors announced that he was discharged from the hospital in Las Vegas.

Sanders was treated for a blocked artery after experiencing chest discomfort and has cancelled campaign events until further notice.

Sanders is the oldest candidate vying to take on President Donald Trump, 73, and is third in the Democratic nominee polls behind Joe Biden, 76, and Elizabeth Warren, 70.

Last month, he cancelled three events in South Carolina to rest his voice, which had become hoarse.

The US senator from Vermont has been among the top contenders in the crowded field seeking the 2020 nomination to challenge Republican President Donald Trump.

(With inputs from agency)