相关链接：不满公投结果，英国民众集会呼吁第二次公投 知乎用户 英国退欧盟虽然已经确定，但是需要走完剩下的手续。 首先生效的是欧洲宪法条约第 56 条，该条约没有实质性内容，该条约生效后，里斯本条约第 50 条生效。 根据欧盟基本条约（里斯本条约）第 50 条（退欧条款）规定： • 1. Any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements. • 2. A Member State which decides to withdraw shall notify the European Council of its intention. In the light of the guidelines provided by the European Council, the Union shall negotiate and conclude an agreement with that State, setting out the arrangements for its withdrawal, taking account of the framework for its future relationship with the Union. That agreement shall be negotiated in accordance with Article 218(3) of the Treaty on the Functioning of the European Union. It shall be concluded on behalf of the Union Functioning of the European Union. by the Council, acting by a qualified majority, after obtaining the consent of the European Parliament. • 3. The Treaties shall cease to apply to the State in question from the date of entry into force of the withdrawal agreement or, failing that, two years after the notification referred to in paragraph 2, unless the European Council, in agreement with the Member State concerned, unanimously decides to extend this period. • 4. For the purposes of paragraphs 2 and 3, the member of the European Council or of the Council representing thewithdrawing Member State shall not participate in the discussions of the European Council or Council or in decisions concerning it. A qualified majority shall be defined in accordance with Article 238(3)(b) of the Treaty on the Functioning of the European Union. • 5. If a State which has withdrawn from the Union asks to rejoin, its request shall be subject to the procedure referred to in Article 49. 总结一下。 1，退出欧盟必须遵循其（英国）本国宪法 2，决定退出欧盟后，退出国必须和欧盟之间达成关于退出后关系的协定 3，在正式宣布退出后，退欧协议必须在 2 年内生效 4，并且该协议需要经过欧洲理事会和欧洲议会通过 5，退欧之后如果想重新返欧，则按照新成员国对待 首先关于退欧声明，应当在 6 月 28 号- 29 号的欧盟首脑会议就宣布。接下来，欧洲理事会（除英国外）应当在 7 月左右就制定好谈判计划和方针，紧接着谈判开始。一般最快能在 2018 年制定出退欧议定案，首先这个议定案需要在欧洲议会过半数通过，其次要在欧洲理事会特定多数通过（27 国中 20 国通过，且人口占欧盟 65% 以上），最后英国正式退欧。 但是需要注意的是，如果全体欧盟成员同意，这个过程可以被延长，也就是说超过 2 年。 谈判的过程应当很漫长，首先英国退欧之后，原本在欧盟中享受的一系列优惠全部消失。而且在经济，组织结构，环境政策，劳动法规等方面也需要重新协商。 由于英国退欧，所以英国和欧盟间的自由贸易协定消失，可能会试图加入 EFTA 获得贸易上的好处，且最后，英国需要和欧盟之外的 53 国重新缔结自由贸易协定（之前英国为 EU 成员，退欧之后，相关协定需要重新缔结） 因此谈判时间 2 年可能不太够…… 过程如下图。 据此回答问题： 1，决定退欧只是第一步，其他手续根据里斯本条约第 50 条，如上图所示 2，谈判时间一般为 2 年 3，英国最快应当能在 2018 年 6 月正式退欧 4，不排除可能性欧盟成员国全体同意导致退欧谈判延长（超过 2 年） 英国目前才刚走完第一步（根据本国宪法公投），剩下的步骤还有很长时间。 阅读原文
