Northern Ireland Secretary Theresa Villiers believes claims that a Brexit could threaten the peace process are "irresponsible and dangerous".
The Vote Leave campaigner said there is strong support in Northern Ireland for an "entirely peaceful future" and the commitment to peace and democracy would not be weakened if Britain is no longer part of the EU.
Remain supporters have warned financial and political support from the EU which has bolstered the Good Friday Agreement would be put at risk should Britain leave.
Labour peer Lord Mandelson, a former Northern Ireland Secretary, also claimed the return of a "hard border" with the Republic would only strengthen extremists.
Asked if the deal would unravel should voters support Britain leaving the EU, Ms Villiers, told Murnaghan on Sky News: "No, I don't believe it would and actually not many people have made that allegation - just one or two figures from the Remain campaign.
"I think that's scaremongering of the most irresponsible and even dangerous kind because what they're effectively saying is that a vote to leave the EU would somehow weaken the commitment of people in Northern Ireland to peace and democracy, weaken their commitment to their future being determined by democracy and consent.
"I don't believe that's going to happen. There is strong support for an entirely peaceful future for Northern Ireland and I think it's deeply irresponsible of those in the Remain camp to suggest otherwise."
Ms Villiers also reiterated she believes border arrangements between Northern Ireland and the Republic would not have to change in the event of a Brexit.
She also dismissed the need for border checks.
Ms Villiers said: "I think the land border we share with Ireland can be as free-flowing after a Brexit vote as it is today."