The UK's most senior business boss will urge politicians "not to throw away a generation of progress" at a high-profile event tonight.
Carolyn Fairbairn, director general of the CBI, will also call for a new customs union with the EU as she addresses the organisation's annual Northern Ireland dinner tonight.
At Belfast's Waterfront Hall, she will call on politicians in Northern Ireland, Westminster and in the EU to ensure a hard border is avoided, and that the powersharing Executive is restored. Without an Executive, she believes, Northern Ireland has "no voice" in Brexit negotiations. Ms Fairbairn will say that, 20 years on from the Good Friday Agreement, "politicians must make sure they do not turn the clock back on peace and prosperity".
The CBI said the Agreement of 1998 had been a catalyst for economic growth.
"In the 20 years since the Good Friday Agreement and the border barriers were taken down, Northern Irish businesses have helped create over 160,000 extra jobs, unemployment is close to its lowest ever, Irish product exports have risen at an average of 6% a year, year on year, for 20 years.
"And companies in Northern Ireland generate £70bn a year in sales."
Ms Fairbairn will say that "debate" is no longer enough and that solutions were needed.
"A hard border must be avoided - if there are alternatives to a customs union that deliver this, they must be explained in detail, now. A functioning Executive is urgently needed - to drive the development of a new economic plan and give Northern Ireland back its powerful voice on the international stage.
"And an immigration system must be laid out that enables businesses to attract the people that will power long-term prosperity."
Ms Fairbairn will add the UK Government need to explain "precisely" how a soft border will be achieved after Brexit. "Now is the time to replace warm words with wise decisions."
The audience will be told Northern Ireland is at a crossroads. "To reaffirm the principle of consent that underpins that agreement and its legacy of civil rights, prosperity and peace or to see a new division across the island of Ireland, with all that that entails for people's jobs, rights and livelihoods. Don't throw away a generation of progress in Northern Ireland on the back of Brexit." The CBI chief will also call for an end to "prevarication" over the border on the island of Ireland.
"We at the CBI have said that a new customs union with the EU will help keep the border open and allow Northern Ireland to continue to prosper.
"Based on current evidence it is the only way to keep the border fully open.
"This is not a dogmatic view but a pragmatic one.
"Technology solutions may be ready one day but they are not yet. And trade deals around the world may one day compensate for lost EU trade. But that day is not yet here.
"So both sides should explore new customs union options, alongside ways to keep goods regulation closely aligned - the other essential ingredient of a wholly frictionless border.
"And while we are making this argument in Westminster we are also making it in the EU27.
"Because they too have much to lose from a hard border in Ireland. And much to gain if we get it right.
Ms Fairbairn will add business in Northern Ireland is now providing a voice which is lacking from politicians.
"Northern Ireland has now been without an executive for 16 months.
"There's no Programme for Government, no industrial or economic strategy and no corporation tax cut that would have brought NI in line with the Republic of Ireland.
"Crucially, there is no directly elected voice of devolved government in the Brexit negotiations.
"This is not how it should be."
"What is so remarkable is that Northern Irish business has not thrown its hands up in despair.
"Where leadership is lacking, business has taken the lead."