- Barnier said he was honoured to continue working with the commission "for a few weeks".
BRUSSELS: Michel Barnier, the EU's chief Brexit negotiator, is to become a special adviser to European Commission President Ursula von der Leyen on the treaties ruling Britain's life outside the bloc.
"I am pleased to share that Michel Barnier has been appointed special adviser to the president," Commission Vice President Margaritis Schinas told a media conference.
"He will advise our president on the implementation of the Withdrawal Agreement, as well as on the ratification process and the Trade and Cooperation Agreement (TCA)," he said.
In a tweet, Barnier said he was honoured to continue working with the commission "for a few weeks".
And he said he would continue working with EU member states and the European parliament "to ensure smooth ratification on the EU side" of the Brexit withdrawal treaty and associated agreements.
Schinas also said European Commission vice president Maros Sefcovic would be the EU representative on a Joint Partnership Council to be set up with Britain that is to guide interpretation of the TCA.
Sefcovic already chairs the Joint Committee overseeing implementation of the Withdrawal Agreement.
In a statement, the Commission said that its Task Force for Relations with the United Kingdom, headed by Barnier, would cease to exist on March 1 and would be replaced by "a new Service for the EU-UK Agreements".
That service will be part of von der Leyen's secretariat general.
Barnier, who reached the Commission's mandatory retirement age of 70 on January 9, will become special adviser from next month, Schinas said.
Issues likely to be priorities for Barnier will be trade frictions between Northern Ireland and the rest of the UK that have left some supermarket shelves bare, and the EU's ratification of the TCA.
While Britain's parliament has already enshrined the TCA into UK law, the EU is implementing it provisionally, pending ratification by the European Parliament.
The TCA stipulates that EU ratification must happen by February 28, but the Joint Partnership Council could agree to delay that if more time is needed.