1. A contract which contains no provision for termination and does not provide for termination or withdrawal is not subject to termination or revocation, unless it has become even more controversial because one of its main objectives is to allow ministers to adopt regulations, even if they violate the withdrawal agreement with the EU under the Northern Ireland Protocol. As long as the agreement of the other party can be obtained, one country can withdraw from any international agreement. This provision is supported by Article 54 of the 1969 Vienna Convention on Treaty Law, which stipulates that the termination of a contract or the withdrawal of a party may be a) in accordance with the provisions of the treaty; or (b) at any time, with the agreement of all parties, after consultation with the other States Parties. But could the UK denounce the withdrawal agreement in accordance with the provisions of the Vienna Convention on Treaty Law (VCLT)? The VCLT sets out limited circumstances in which a contract may be terminated if it does not contain relevant whistleblowing clauses and the parties cannot be brought into compliance. In these circumstances, there are cases where Newman stated: „What Number 10 must agree with the EU is a legally binding ancillary agreement which specifies that the UK would reserve the right to cancel the withdrawal agreement under the Vienna Convention if the negotiations do not take place in good faith.“ Some commentators have suggested that either the „substantial violation“ (Article 60) or the „fundamental change in circumstances“ (Article 62) of the provisions of the VCLT could allow the United Kingdom to unilaterally denounce the agreement or denounce it if the Irish backstop were to become permanent. But there are difficulties with these proposals. It would be extremely difficult to demonstrate a „substantial violation“ of „best efforts“; and it is essential that the continuation of the backstop is not a „fundamental change in circumstances“ within the meaning of the VCLT. It is set out in the protocol; these are potential negative effects and the protocol provides a mechanism to deal with such a situation. This blog post will provide a closer look at the history and purpose of Article 50 of the EU TREATY and the legal nature of the withdrawal agreement. The vagueness of Article 50 kills can be explained by its political dimension. Philippe Sands QC, professor of international law at University College London, said: „Any international jurist is familiar with the Vienna Convention on Treaty Law and Article 27, which reflects a general principle: „A party cannot invoke the provisions of its domestic law to justify its non-compliance with a contract.“ This would indeed mean dissolving a global agreement and leaving, but proponents of this possible approach argue that there is international protection, which is defined by the Vienna Convention, a legal text that sets the rules governing treaties. Britain only has to inform the EU of its intention to leave the country, and 12 months later, kabam! – No withdrawal agreement and therefore no backstop.

Legal loopholes and linguistic inaccuracy lead to particular uncertainties about the withdrawal agreement that the EU and the withdrawn Member State must approve.