Tracey Crouch has resigned as Sports and Civil Society Minister amid a row over delays to cut the maximum stake for fixed-odds betting terminals (FOBTs).
Ms Crouch is unhappy the cap on FOBTs bets being reduced from £100 to £2 will not come in until October 2019.
The MP tweeted: “It is with great sadness I have resigned from one of the best jobs in Government. Thank you so much for all the very kind messages of support I have received throughout the day. Politicians come and go but principles stay with us forever.”
In her resignation letter to Prime Minister Theresa May, Ms Crouch said: “Unfortunately, implementation of these changes are now being delayed until October 2019 due to commitments made by others to those with registered interests.
“From the time of the announcement to reduce stakes and its implementation, over £1.6 billion will be lost on these machines.
“In addition, two people will tragically take their lives every day due to gambling-related problems and, for that reason as much as any other, I believe this delay is unjustifiable.
“I know there is never a good time to resign and appreciate that this will be an unwelcome distraction, but as the Secretary of State for Digital, Culture, Media and Sport said in the House this morning, it is a fact of Government that ministers must adhere to collective responsibility and cannot disagree with policy, let alone when it is policy made against your wishes relating to your own portfolio.”
The move came after the Government made it clear it was standing firm when Chief Secretary to the Treasury Liz Truss failed to give ground during the Budget debate in the Commons.
Ms Truss told MPs that the Government is “certainly happy to discuss” the matter, but gave no indication of a change of policy.
Ms Crouch has been a leading campaigner in reducing the maximum stake for FOBTs.
Former Tory leader Iain Duncan Smith joined cross-party calls to bring the change forward to April 2019.
Tom Watson, the shadow culture secretary, tweeted praise for Ms Crouch saying: “She poured her heart and soul into a significant review of these destructive machines, faced down a systematic lobbying attempt by the gambling industry and took the right decision for those suffering from problem gambling, their families and communities.”
Mr Watson blamed Digital, Culture, Media and Sport Secretary Jeremy Wright for the delay, saying: “The new Secretary of State has threatened all of this good work. He has prioritised corporate interests over victims, profits over public health and greed over good. He should be thoroughly ashamed.”