Iain Duncan Smith has promised to fight demands from Brussels to “open our doors to benefit tourists”.
The work and pensions secretary told the Conservative conference that his response to any European Commission requests to give money to more out-of-work immigrants would be: “No. No. No.”
He also said the government would reward marriage in the tax system.
This would help prevent a repeat of the riots which blighted English cities this summer, Mr Duncan Smith argued.
The European Commission has threatened legal action against the UK over its rules on welfare, which include a “right-to-reside” test.
It said last week that it wanted the government to adopt EU-wide rules instead.
Mr Duncan Smith, who was Conservative leader from 2001 to 2003, argues this is undemocratic and an infringement on national sovereignty, which could cost £2bn a year.
He received applause when he told delegates in Manchester: “Let me re-assure you that, at a time when the British people are tightening their belts, and the European Commission orders us to open our doors to benefit tourists and pay them benefits when they arrive here.”
Echoing the words with which former Prime Minister Margaret Thatcher rejected the possibility of giving further powers to Brussels in 1990, he added: “I have a simple message for them. No. No. No.”
In a wide-ranging speech, he also promised that the government would “recognise marriage in the tax system”.
He said: “This isn’t about government interfering in family life; it’s about government recognising that stable two-parent families are vital for the creation of a strong society.
“It’s about parents taking responsibility for their children. It is about government realising that we have to create a level playing field for the decisions people make about family.
“This means reversing the biases against stability we’ve seen in recent years, including the damaging financial discouragement to couple formation, despite the evidence of its stable outcomes for children.”
The streets near the Manchester Central conference centre were the scenes of some of the worst unrest during August’s riots.
Mr Duncan Smith described such violence and looting as “a wake-up call on street gangs”.
He said: “Gang members were not the sole perpetrators of the riots but they played a significant part.
“I have seen how these gangs destroy lives in my own borough – the young murdering the young.”
Mr Duncan Smith added: “Many young gang members drift in from dysfunctional broken backgrounds, in search of a place to belong, a perverse kind of family, others through fear of retribution.
“With no role models except the violent and the criminal, like child soldiers of the Third World these young minds bear the deep scars of a life filled with anger and violence.
“Fighting this through our police forces is crucial, but this isn’t a job for officers alone; we must end the false belief that we can arrest our way out of this crisis…
“Dealing with Britain’s violent gang culture is vital because the simple truth is that that where gangs rule, decent people cannot live. ”
But Rhian Beynon, of the group Family Action, said: “For all he professes to be a family man, Iain Duncan Smith’s policies are hurting families and children.”
She added: “If the secretary of state is serious about turning round entrenched family breakdown the Government must support the most vulnerable families through these tough times with better services and improved benefit levels rather than slashing them to the bone.”