Lord Peter Mandelson
Lord Peter Mandelson, former EU commissioner and British business secretary Getty

New Labour co-architect Lord Peter Mandelson will advise Sadiq Khan on the Brexit negotiations between the UK and the EU, the Mayor of London announced on Monday (19 December).

Mandelson, a former EU commissioner and British business secretary, will be joined on a panel of experts by Santander UK chair Baroness Vadera, London Stock Exchange boss Xavier Rolet and PwC immigration expert Julia Onslow-Cole.

"This expert group of advisors will allow me to tap into some of our top business minds as negotiations progress," Khan said.

The Brexit Expert Advisory Panel is designed to help provide the Labour Mayor with "insight and expertise" as he presses the government over the UK's split from the EU.

Khan is currently holding monthly meetings with Brexit Secretary David Davis. "I have promised to be most pro-business Mayor that London has ever had – and now I'm delivering on that promise," he said.

"For the last six months, I have been speaking to businesses of all shapes and sizes about what they need from the forthcoming Brexit negotiations.

"We need to strike a deal that safeguards London's position as the best city in the world to do business and this expert group of advisors will allow me to tap into some of our top business minds as negotiations progress."

Mandelson and Khan were both prominent Remain campaigners ahead of the EU referendum. But the appointment also comes after the pair clashed during Labour's 2010 leadership election, which saw Khan serve as Ed Miliband's agent.

The Mayor of London said Labour members would not be "convinced by hearing the same old messages from the New Labour attack machine" in reaction to criticisms Mandelson made of Miliband.

Prime Minister Theresa May has promised to invoke Article 50, the official mechanism to split from the EU, by the end of March 2017.

But MPs will have to vote on the issue if the government's appeal to the Supreme Court fails. A final ruling is expected in January.