Here is the full text of the letter sent by Boris Johnson to European Council President Donald Tusk to meet the requirements of the Benn Act:

Dear Mr President,

The UK Parliament has passed the European Union (Withdrawal) (No.2) Act 2019. Its provisions now require Her Majesty’s Government to seek an extension of the period provided under Article 50(3) of the Treaty on European Union, including as applied by Article 106a of the Euratom Treaty, currently due to expire at 11.00pm GMT on October 31, 2019, until 11.00pm GMT on January, 31 2020.

I am writing therefore to inform the European Council that the United Kingdom is seeking a further extension to the period provided under Article 50(3) of the Treaty on European Union, including as applied by Article 106a of the Euratom Treaty. The United Kingdom proposes that this period should end at 11.00pm GMT on January 31, 2020. If the parties are able to ratify before this date, the Government proposes that the period should be terminated early.

Yours sincerely,

Prime Minister of the United Kingdom of Great Britain and Northern Ireland

Unsigned letter from Boris Johnson to Donald Tusk
Unsigned letter from Boris Johnson to Donald Tusk (UK Government/PA)