Brussels will "start to set the rules for the NHS" if the UK votes to remain in the EU, Chris Grayling will warn.
The pro-Brexit Cabinet minister is set to claim that major reform plans for deeper integration are being kept under wraps ahead of Britain's EU referendum on June 23.
But the plans will go "full steam ahead" if the country votes in favour of remaining in the bloc.
"If we vote to remain in the EU then it would be EU rules that would determine our minimum wage, EU rules that would say how our pensions work", he will say in a speech in London.
"It would be EU rules to govern our skills system and even EU rules that would tell us how health services should work".
Mr Grayling will say that pro-EU campaigners were right to promise reform but that inevitable reform is "very different" to what they aspire for.
He will also reject rivals' claims that Brexit campaigners would seek to weaken social protections once the UK was no longer bound by Brussels rules.
"Let me make clear that I do not want to see social rights and protections diminished if we vote to leave the EU," he will say.
"The point, however, is whether it is for the EU or for the people of the United Kingdom to control our rights and protections".
Labour's campaign has focused heavily on Brussels' role in reinforcing workers' rights, accusing Tories of wanting to water them down.
Other plans will be kept quiet until after the referendum, he will say.
"We know the (European) Commission is on its best behaviour right now. Everyone in Brussels is under strict instructions not to rock the boat. Frankly I am surprised that they have even started the consultation on the Social Pillar.
"But the decision to delay anything controversial in Brussels until after our referendum is an open secret there. Legislation is being held back. The budget is being held back. The EU institutions are in lock down until the British decision is done and dusted.
"If we vote to remain, the plans move full steam ahead".