The decision on Thursday is viewed as a response to the letter from British Ambassador to the EU Tim Barrow Wednesday, in which he stated that London will not nominate an EU commissioner until after its December 12 national election, Xinhua news agency reported.
Each of EU's 28 member states is required to nominate an EU commissioner to serve in the European Commission.
EU leaders have asked Britain to pick a candidate and made this a condition of granting a Brexit extension until January 31, 2020 when they met last month.
But for Britain, it is believed that the government should not put forward candidates for senior international appointments, including to European institutions, during an election period.
Barrow's letter raises the possibility of a further delay in the new European Commission taking office.
Commission President-elect Ursula von der Leyen and her new College of Commissioners were supposed to take office on November 1.
The British authorities have until November 22 at the latest to provide their views, to make sure that the next Commission could enter into office as soon as possible. If no observations are submitted within this time limit, the Commission may, if appropriate, issue a Reasoned Opinion.
If the Commission concludes that the country is failing to fulfil its obligations under EU law, it may send a Reasoned Opinion: a formal request to comply with EU law. It explains why the Commission considers that the country is breaching EU law.
( With inputs from IANS )