Labour is pursuing plans to force bookmakers to pay a new levy to help fund NHS treatment of problem gamblers.
Deputy leader Tom Watson will accuse gambling companies of deliberately targeting vulnerable people "driven by greed" in a speech at Labour's conference.
The shadow culture secretary will condemn the firms for an "abuse of trust and power" and liken their action to drinks manufacturers "selling vodka outside AA meetings?"
Mr Watson will tell the Brighton conference on Tuesday: "The number of problem gamblers in this country has risen by a third in just three years.
"Two million people are either problem gamblers or at risk of addiction. Children and young people are being targeted by betting advertisers more than ever.
"We now know that when vulnerable people try to opt-out of online gambling, companies don't always block their accounts, as they should."
The NHS' ability to provide mental health treatment for addicts and problem gamblers will also be examined.
Mr Watson will say the Labour review "will assess the feasibility of making the gambling industry pay a compulsory levy to fund NHS treatment and help lift problem gamblers out of the destructive cycle of addiction.
"At the moment, the industry is asked to make voluntary contributions of 0.1% of profits - but it doesn't."
GambleAware asks the industry to donate 0.1% of gross gaming yield to fund education, prevention and treatment services.
But Labour said the firms contributed just £7.6 million rather than the £13.8 million that could have been provided.
Mr Watson will add: "So my message to gambling firms today could not be clearer: stop targeting vulnerable people. Start acting responsibly.
"And meet your obligation to help those whose lives been blighted by addiction."
Labour has already set out plans to cut the maximum stake at fixed-odds betting terminals from £100 to just £2 and to ban bookmakers from sponsoring football teams.