The Wire hitmakers appeared on a Bbc political Tv show in September (13) and dedicated a song to fellow guest Cameron before handing him a Cd of their album and posing for a snap.
However, former The Smiths star Marr is adamant the girls made "idiots" of themselves by cosying up to the right-wing Conservative Party leader and has warned them not to risk looking "uncool by association".
In an article for NME magazine, he writes, "As for Haim having their photograph taken with David Cameron, it's really simple: they made themselves look like idiots. It's ridiculous. No one put a gun to their head. The Conservatives tried to do the same thing to The Smiths, to re-appropriate us in a false way, to be cool by association. And let's put it this way in the case of Haim: it's uncool by association."