makers could face greater taxation as Labour proposes an extension of the horseracing levy.

The existing levy takes 10.75% of horseracing profits, but a new 'More Sport for All' dossier from Harriet Harman and shadow culture secretary Clive Efford considers extending the tax to all sports.

Efford said: “We believe it is right that businesses that make money from sport should contribute to sport. We are consulting on whether we should introduce a levy on betting, including online betting, to fund gambling awareness and support for problem gambling but also to improve community sports facilities and clubs."

The UK gambling industry reported more than £6bn revenue after winnings were paid in 2012-13.

"Football gambling online and in betting shops is now far larger than horseracing gambling and yet it does nothing to help the sport itself." said Efford. "I think they have a moral obligation to help the industry from which they make billions, and the results could be dramatic.”

The announcement has impacted UK betting stocks, with Ladbrokes and William Hill down 3%.