MP: Sack the Lotto.
The call came as punters threatened a boycott in protest at the cost of tickets doubling.
More than nine out of 10 people said in an online poll the price hike will stop them playing.
Efford fears good causes who rely on the lottery could go short. He said operator Camelot had jacked up prices when people could least afford it to compete with EuroMillions, but predicted they would fail.
"If that means that the lose their contact then so be it," he said. And former sports minister Gerry Sutcliffe warned: "It might encourage people to spend more than they can afford."