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'Resist urge to control e-cigarettes', WHO told

29 May 2014 Last updated at 06:51 BST

Fifty scientists from Europe, North America, Asia and Australia have signed a letter calling on the World Health Organization not to seek stringent controls on electronic cigarettes.

They say the products should instead be regarded as a "significant health innovation", but doctors' leaders say too little is known about the long-term effects.

Jane Dreaper reports.