Greenland has decided to leave its predecessor from the EU without seceding from a member state. It first voted against accession to the EEC when Denmark joined in 1973, but because Denmark as a whole voted to join, Greenland also joined as a county of Denmark. When Greenland`s self-government began in 1979, he held a new referendum and voted to leave the EEC. Following disputes over fishing rights, the area left the EEC in 1985, but remains subject to the EU Treaties by the association of overseas countries and territories with the EU. This was made possible by the Greenland Treaty, a special treaty signed in 1984 to allow its withdrawal.  However, following the withdrawal of the United Kingdom from the EU, the right of residence of British nationals and their family members will no longer result from Directive 2004/38, but from the Withdrawal Agreement. As of June 2020, no country other than the UK had voted on whether to leave the EU, with political parties criticising the European Union`s federal trend and advocating withdrawal gaining prominence in several member states since the 2014 European Parliament elections, as has the rise of UKIP in the UK. Previously, no provision of the Treaties or EU law described the possibility for a state to voluntarily withdraw from the EU. The absence of such a provision made revocation technically difficult, but not impossible.
 Legally, there were two interpretations as to whether a state could withdraw. First, that sovereign States have the right to evade their international obligations;  and second, the Treaties apply for an unlimited period of time, without withdrawal provisions and without the requirement of an “ever closer union” – such a commitment to unification is incompatible with unilateral withdrawal. The Vienna Convention on the Law of Treaties stipulates that in cases where a party wishes to withdraw unilaterally from a treaty that says nothing about secession, there are only two cases where withdrawal is permitted: when all parties recognize an informal right in this regard and the situation has changed so radically that a signatory`s obligations have been radically altered.  The Treaties do not apply to the Member State concerned from the date of entry into force of the Withdrawal Agreement or, in the absence of such an agreement, two years after the Member State has notified the European Council of its intention to leave the EU, although this period may be extended by unanimity of the European Council.  This site contains more detailed information on citizens` rights after the UK`s withdrawal. Several states have political parties represented in national assemblies or in the European Parliament that are in favour of leaving the EU.  British nationals and their family members residing in Luxembourg at the time of the UK`s withdrawal are also entitled to employment after the UK`s withdrawal without having to apply for a special authorisation. The residence permit of the persons concerned shall remain valid until it is replaced by a new residence permit attesting to their status as beneficiaries of the Withdrawal Agreement. Article 50 does not specify whether Member States may withdraw their notification of their intention to withdraw during the negotiation period while their country is still a member of the European Union.
However, the President of the European Council told the European Parliament on 24 October 2017 that “Deal, No Deal or No Brexit” depends on the United Kingdom. In fact, the dominant legal opinion among EU legal experts and the EU institutions themselves is that a member state that intends to withdraw may change its mind, since an “intention” is not yet an act and intentions may change before the act is done.  At the time the Scottish Government did so in late 2018, the issue had not been challenged in court. On the 10th. In December 2018, the Court of Justice of the European Union ruled that “it would be incompatible with the objective of the EU Treaties to create an ever closer union between the peoples of Europe, to force the withdrawal of a Member State”, and that, therefore, a notification under Article 50 can be unilaterally revoked by the notifying member without the authorisation of the other EU members. unless the state has already left the EU and the revocation is decided “according to a democratic procedure in accordance with national constitutional requirements”.    British nationals and their family members who reside in Luxembourg and are employed in Luxembourg at the time of the United Kingdom`s withdrawal may therefore continue to work after the United Kingdom`s withdrawal. They do not need special permission and do not need to take steps to continue their work. The government has reached an agreement with Switzerland to protect citizens` rights. British nationals and their family members arriving in Luxembourg after the withdrawal of the United Kingdom and before the end of the transition period (31 December 2020) will also have free access to the labour market.
The Agreement shall be concluded by the Council on behalf of the Union and shall lay down the withdrawal arrangements negotiated in accordance with Article 218(3) of the Treaty on the Functioning of the European Union, including a framework for the future relationship of the State with the Union. The agreement shall be approved by the Council, acting by a qualified majority after obtaining the consent of the European Parliament. If a former Member State were to try to rejoin the European Union, it would be subject to the same conditions as any other candidate country.  Other EU members would have to deal with the resulting changes in EU budgets, voting allocations and policies resulting from the withdrawal of a Member State.  There are no clear agreements, treaties or precedents covering the scenario of a disintegration of an existing EU Member State into two or more states. .