The Daily Mail has exposed a secret letter Lord Mandelson sent to the European Commission's chief Brexit negotiator Michel Barnier, in which Mandelson promised to adhere to the EU's principles in the future. The letter was obtained from the European Commission using Freedom of Information laws.
"As you know, I am deeply committed to the future of the EU as it strives for solidarity in the face of growing challenges from populist movements, geopolitics and a still-recovering economy," Mandelson, the former European Commissioner for Trade, said.
He added that he would like "to put some time aside for us to share some thoughts on the Brexit negotiations."
Mandelson also promised Barnier to brief him on "the current pressures in British politics" and "how these will play out."
Barnier's office, in turn, expressed his 'sincere thanks' for the offer but said they would be unable to arrange a meeting for the dates suggested by Lord Mandelson in the letter, which came after the two men attended a Brussels conference in November 2017.
Lord Mandelson has more than once criticized the British government's stance on Brexit, which he argued could be postponed because "voters were not told the truth about leaving the EU."
In particular, no one had been warned before the Brexit referendum that Britain would leave the single market, according to Mandelson.
Brexit negotiations between the United Kingdom and the European Union kicked off on June 19, 2017 and are due to wrap up by the end of March 2019.
The talks' first phase focused on the protection of EU citizens' rights in the UK, the British-Irish border and London's financial obligations to Brussels after the withdrawal.
The second stage began in December and concentrates on the transition period in EU-UK ties after Brexit and future trade and security collaboration between the parties.