Brexit will not mean "a return to the border posts of the past" between the Republic of Ireland and Northern Ireland, the government has insisted.
The latest UK position paper on leaving the EU will make clear that a return to the security arrangements which were in place before the Good Friday Agreement would be "completely unacceptable".
Instead, ministers will insist that innovative solutions must be found to ensure "frictionless" trade can continue between the two countries.
They could include the EU and UK aligning their customs approaches in Ireland, ensuring that the current arrangement - where there is effectively no border - remains in place.
The government will also propose a continued waiver on submitting entry and exit declarations, and continued membership of the Common Transit Convention to help Northern Ireland and Irish companies transit goods.
Britain also wants to maintain the Commons Travel Area between Britain and Ireland, which pre-dates the EU, and protect the rights of British and Irish citizens contained in the Good Friday Agreement.
A UK government source said: "Both sides needs to show flexibility and imagination when it comes to the border issue in Northern Ireland and that is exactly what our latest position paper will do.
"As (EU chief negotiator) Michel Barnier himself has said, the solution cannot be based on a precedent so we’re looking forward to seeing the EU’s position paper on Ireland.
"But it’s right that as we shape the unprecedented model, we have some very clear principles. Top of our list is to agree up front no physical border infrastructure — that would mean a return to the border posts of the past and is completely unacceptable to the UK.
"Our paper sets out some creative options on customs and shows the priority we place on making progress on this."
But Conor McGinn, a Northern Ireland-born Labour MP who backs the pro-EU Open Britain group, said: "The government is right to reiterate its pledge not to return to the borders of the past, but even this language shows how far along the road of regression we have travelled since Brexit.
"After 20 years of progress and cooperation on the island of Ireland and between the UK and Ireland, the government's vagueness and posturing is squandering the goodwill of our nearest neighbour and strong ally.
"These proposals on a light touch border are lighter still on detail. They don't outline how a frictionless or seamless border can be achieved when the UK leaves the EU and won't reassure anybody about the impact of Brexit on Northern Ireland."
Josh Hardie, deputy director general of the Confederation of British Industry, said businesses "need to see much more detail from these papers".
“Over the last two decades, Northern Ireland’s economic growth has been built on a foundation of peace and political stability. It is vital that any future border arrangement does not jeopardise the significant progress made as a result of the strong foundations established by the St Andrews/Good Friday Agreements," he said.
“Business has been clear that maintaining an open, frictionless border between the Republic of Ireland and Northern Ireland, and between Great Britain and the island of Ireland is essential to supporting jobs and the economy."