In a feisty fundraising email sent to supporters on Wednesday, Vermont Sen. [crscore]Bernie Sanders[/crscore] accused Hillary Clinton of being too cozy with health care and pharmaceutical companies, asserting that the Democratic front-runner has taken more money in campaign contributions from those industries than the top three Republican presidential candidates combined.

“Now, and let’s not be naive about this, maybe they are dumb and don’t know what they are going to get?” Sanders wrote of the health care and pharmaceutical companies. “But I don’t think that’s the case, and I don’t believe you do either.”

The email marks perhaps the most aggressive shot Sanders has taken at Clinton, who has endorsed Obamacare. In contrast, the 73-year-old democratic socialist supports a single-payer, nationalized health care system.

According to Sanders, one factor holding Clinton back from supporting single-payer — which he asserts will guarantee health care to all — is that the former secretary of state “has received millions of dollars from the health care and pharmaceutical industries.”

The donations, which are “sure to rise as time goes on,” are greater “than did the top 3 Republicans — combined,” Sanders wrote.

It is not exactly clear which statistics the Sanders campaign is citing with the claim. But Clinton’s campaign did receive more in donations from the drug and medical device industries than any candidate from either party during the first six months of the campaign, according to The Boston Globe.

And according to the Republican opposition research group America Rising, Bill and Hillary Clinton have raked in between $1.6 million and $2.6 million in speaking fees from pharmaceutical companies or industry trade associations.

That despite Clinton claiming during the first Democratic debate in October that she considers drug companies to be one of her political enemies.

While Sanders has criticized Clinton for not being progressive enough on health insurance coverage, the former first lady has argued that such a scheme would require a heavy tax increase on the middle class. Sanders has pushed back, saying that Clinton’s analysis of his plan does not take into account how much money consumers will save by not having to pay for insurance plans out of pocket.

Sanders’ email indicates that the Democratic contest is taking a nastier turn. So far, Sanders has pulled punches against Clinton. He famously refused to criticize Clinton over her use of a personal email account and private email server as secretary of state. Clinton has not been so charitable. She’s accused Sanders of making subtly sexist statements about her stance on guns.

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