HILLARY Clinton's US presidential campaign has fired back at her rival Bernie Sanders after the Vermont senator questioned whether she is "qualified" to be president.
In a fundraising email sent late on Wednesday, Hillary for America's deputy communications director, Christina Reynolds, rebuked Mr Sanders's accusations, saying it was "a ridiculous and irresponsible attack for someone to make - not just against the person who is almost certainly going to be the nominee of their party this November, but against someone who is one of the most qualified people to run for the presidency in the history of the United States".
Mr Sanders told a crowd of more than 10,000 people at Temple University's Liacouras Centre in Philadelphia on Wednesday that Mrs Clinton has been saying lately that "she thinks that I am, quote-unquote, not qualified to be president."
"I don't believe that she is qualified if she is, through her super PAC, taking tens of millions of dollars in special-interest funds," he said, referring to the outside groups that can accept unlimited funding for a candidate as long as they do not coordinate with the campaign.
Mr Sanders also said Mrs Clinton is not qualified because of her vote for the war in Iraq and her support for trade agreements that he says are harmful to American workers.
It is the latest salvo in a war of words that has become increasingly heated as underdog Mr Sanders has gained ground on front-runner Mrs Clinton, capped by the Vermont senator's victory in Tuesday's Wisconsin primary.
Mrs Clinton's spokesman Brian Fallon responded quickly to Mr Sanders's comment, writing on Twitter: "Hillary Clinton did not say Bernie Sanders was 'not qualified.' But he has now - absurdly - said it about her. This is a new low."
In a discussion on MSNBC's Morning Joe of an interview with Mr Sanders that appeared in the New York Daily News, Mrs Clinton was asked if "Bernie Sanders is qualified and ready to be president of the United States".
She responded: "Well, I think he hadn't done his homework and he'd been talking for more than a year about doing things that he obviously hadn't really studied or understood, and that does raise a lot of questions."
Mr Sanders's spokesman Michael Briggs said on Wednesday evening that Mr Sanders was responding to reports on the CNN and Washington Post websites. A Post story was headlined, "Clinton questions whether Sanders is qualified to be president".
Later in an interview with Politico, Mrs Clinton said she tries to explain things in a more "open and truthful way than my opponent".
Later, at a Philadelphia job training centre, Mrs Clinton said people should know what she would do if she is elected president, "not just lots of arm-waving and hot rhetoric".
