The UK may unilaterally withdraw its letter sent under Article 50 to withdraw from the EU, the advocate general of the European Court said on 4 December 2018. His opinion is not a judgment, though the Court accepts his opinions in about 80% of cases.
The UK does not need the agreement of the other 27 states to withdraw its letter and remain in the EU. This is the opposite to what the EU itself has said.
The case was brought by a group of opposition politicians. The UK government that they had no standing to bring the action, but this was rejected.
The EU itself opposes this action. Its chief legal lawyer said it would allow member states to “resign” to get better membership terms and then withdraw the resignation.
The government has said it has no intention of withdrawing its letter. [18.12]