By Michael McHugh
Northern Ireland's economy could be almost £5 billion less productive by 2034 following a no-deal Brexit, the CBI said.
The country would be among the most exposed parts of the UK to the fallout, the business group reiterated.
The predicted drop in output represents more than the annual public spending on hospitals, GP surgeries and other health services in Northern Ireland.
Angela McGowan, Northern Ireland director for the CBI, said: "CBI members across Northern Ireland are clear: if the new approach to finding a Brexit deal continues to be a game of who blinks first, the Northern Irish economy will pay the price."
If the UK fails to secure a deal with the EU, by 2034 real Gross Value Added (GVA) - the measure of value of goods and services produced in Northern Ireland - could be 9.1% lower than under the UK's current arrangements with the EU, according to government analysis.
The CBI used that analysis to calculate the £5 billion annual lost output.
It said the predicted shortfall would hit people's jobs, livelihoods and living standards, and added: "Manufacturing activity is particularly important in Northern Ireland, and the agri-food sector, which employs thousands, is likely to be severely impacted as it is particularly exposed to the risk of higher tariffs and trade costs.
"With 57% of Northern Irish goods exports going to the EU, any increased trade friction, added costs or delays would hit the region particularly hard."
Ms McGowan said the deadlock will only be broken by a genuine attempt by all MPs to find consensus and compromise, not stick to "rusting red lines" and political conditions.
She added: "Like the rest of the UK, Northern Ireland is not - and cannot be - ready for no deal.
"The projected impact on our economy would be devastating, and while business will do all it can to reduce some of the worst aspects, a no-deal scenario is unmanageable.
"The message from the CBI to our politicians is clear - we must see compromise or the whole country faces the unforgivable prospect of a disorderly Brexit which will affect jobs and livelihoods in Northern Ireland for decades to come. It's time to put prosperity before party politics and dogma."