The terms have infuriated pro-Brexit lawmakers in embattled Prime Minister Theresa May's Conservative party who say it leaves Britain a "vassal state" of Brussels.
European ministers will approve instructions for chief negotiator Michel Barnier for the transition, which the bloc wants to run from March 29, 2019 -- when Britain leaves the EU -- until December 31, 2020.
The so-called negotiating directives say Britain must follow EU rules "as if it were a member state" during that time but without having any say -- even on laws that are passed after Brexit.
The EU guidelines also say the transition period must be "clearly defined and precisely limited in time".
Talks with Barnier's counterpart David Davis could begin as early as this week, with the aim of completing them by March so negotiations on future trade ties can start, European sources said.
But the transition negotiations could be more complicated than expected, with high stakes, analysts said.