UPDATE 2:

Ireland, Britain and the European Union announced agreement (8 December) to avoid a hard border between the Republic and Northern Ireland. Taoiseach Leo Varadkar said the deal “had “achieved all that we set out to achieve” in this phase of the Brexit negotiations.

Read the full text of the agreement.

UPDATE 1:

The border deal has collapsed, at least for today (4 December), due to DUP objections.

Here’s a good explanation and background story from The Washington Post.

ORIGINAL POST:

Ireland and Britain have reached a deal to prevent the return of a hard border between the Republic and Northern Ireland, according to The Irish Times and other media outlets.

Negotiators have agreed on the term “regulatory alignment” to describe customs rules and trade practices between the north and south of Ireland, rather than a formal commitment to “no divergence” originally sought by Ireland.

The reported deal comes weeks ahead of more wide-ranging Brexit negotiations between Britain and the European Union (of which the Republic remains a member) later this month.

Some early press reports portray the agreement as a concession to Ireland by Britain, which has angered the Democratic Unionist Party. The DUP could block the deal “given Theresa May’s dependence on the party for a working majority in the Commons.”

I’ll update this post as more details emerge.