The "ghettoisation" of Britain's communities is promoting terrorism, shadow Cabinet Minister Caroline Spelman has warned.
The MP for Meriden said Tory plans for a civilian national service would "break down the barriers" and bring people from different backgrounds together.
She led a debate at the Conservative Party conference in Bournemouth on the topic of "social justice".
In a break with tradition, she followed her speech with a question and answer session in which delegates quizzed a panel including the Bishop of Rochester, Michael Nazir-Ali, and John Bird, the editor of the Big Issue.
Mrs Spelman, the shadow Secretary of State for Communities and Local Government, said: "The fracture in our societies between communities that 'have' and those that 'have not' fuels misunderstanding.
"The ghettoisation of our communities breeds fear and distrust.
"At no time has there been a more urgent need to weld our communities together, to break down the barriers which have turned some of our communities into recruiting grounds for terrorists.
"But this cohesion cannot be delivered from central government. We must start by offering opportunities and resources that will bring united communities with shared values."