European Union and British negotiators are closing in on a trade deal with only a disagreement over fishing rights in U.K. waters remaining,

After resolving a few remaining fair competition issues, negotiators were down to dealing with fishing quotas and transition terms as they worked to secure a deal for a post-Brexit relationship by an end-of-year deadline.

Sources on both sides said the long and difficult negotiations were in their final stretch and an announcement of a deal could come Thursday morning. Britain withdrew from the EU on Jan. 31, and an economic transition period expires on Dec. 31. A deal would avert a chaotic break on New Year’s Day.