On 19 October 2019, after a day in the House of Commons which the UK Prime Minister Boris Johnson must have found frustrating (because the Meaningful Vote on his Revised Withdrawal Agreement did not take place), the Prime Minister sent an unsigned letter to the President of the European Council.
The letter was in the format prescribed by the UK's "European Union (Withdrawal) (No.2) Act 2019" – the Benn Act. This would ordinarily be seen as an application to extend the period of notice given to the EU under Article 50 of the Treaty on European Union.
What made the letter somewhat unusual was that it was unsigned and was accompanied by a signed letter from the Prime Minister which sought to undermine it.
Will the EU accept the unsigned letter?
In all probability, the European Council has the ability, legally, to accept it. EU Regulations, Directives and Decisions are published in the Official Journal of the European Union without a signature and just with the typed name of a person approving it. Equally, the judgments of the Court of Justice of the European Union have the typed names of the judges but no signatures. However, treaties are usually printed with copies of signatures. So, it is quite likely that the "pretence" that the Prime Minister did not really send it will not work at the EU level – particularly, as the Prime Minister wrote an accompanying signed letter seeking to undermine it. It is possible that a different result could be reached at the UK national level – e.g., in the Scottish courts - but the EU would hardly trigger a No Deal Brexit by saying that the letter was invalid because it was not signed.
Will the EU extend?
Quite likely. The EU has gone to great lengths to avoid being blamed for, or pushing the UK into, a No Deal Brexit. So, the European Council will probably extend the notice period. The current extension runs out on 31 October 2019. This was when the current Juncker Commission was due to step down but it will not be replaced until 1 December 2019 (or later) as three nominees have been rejected by the European Parliament. The European Council might extend until 30 November 2019 but it could:
extend until much longer – the UK does not have to use the time available – or
not refer to a date but refer to an event or process
So, it is quite likely that there would be an extension and a longer (rather than shorter) extension would avoid this false deadline syndrome continuing unnecessarily – which would be good for society and business.