A coalition of 25 US States has urged MillerCoors not to launch an extension of its alcoholic caffeine drink.

Connecticut attorney general Richard Blumenthal, leading the coalition, said he had written to MillerCoors' chief executive, urging the brewer to abandon its plan to introduce the "alcoholic energy drink", Sparks Red.

Blumenthal said that the mix of alcohol and caffeine content constituted a "danger" to young people.

Separately, nonprofit organisation Center for Science in the Public Interest (CSPI) has filed a lawsuit against MillerCoors in Washington DC, in an attempt to get Sparks taken off the market altogether.

Blumenthal added: "Anheuser-Bush responsibly removed some of its alcoholic energy drinks - including Tilt and Bud Extra - after our coalition of states repeatedly raised concerns about the dangers posed to young drinkers. MillerCoors should follow suit and realize its own moral responsibility to young consumers."

A spokesperson for MillerCoors was not immediately available for comment at the time of publication.