BRUSSELS (AP) — British Prime Minister Boris Johnson and his 27 counterparts from across the European Union are converging on Brussels for a summit they hope will finally lay to rest the acrimony and frustration of a three-year divorce fight.

Yet high anxiety still reigned on Thursday morning with the last outstanding issues of the divorce papers still unclear and Johnson uncertain whether his allies at home will back the compromises he needs to make a deal.

Technical negotiators again went into the night Wednesday to finetune customs and VAT regulations that will have to regulate trade in goods between the Northern Ireland and Ireland, where the UK and the EU share their only land border.

The summit starts midafternoon and is slated to end some 24 hours later.