Boris Johnson has appointed former chief Brexit negotiator Lord Frost to the cabinet. The new role is his fourth this year – an impressive feat considering we haven’t even got to the end of February.

As a Minister of State in the Cabinet Office, but with full cabinet rank, it’s back to Brexit for diplomat David Frost. He will, says, Number 10, “lead the UK’s institutional and strategic relationship with the EU and help drive through changes to maximise the opportunities of Brexit, including on international trade and economic issues.”

This includes co-ordinating relations with the EU institutions and the 27 member states, and “leading on central coordination and policy resolution on international trade policy”.

Number 10 said: “The Queen has been pleased to approve the appointment of Lord Frost CMG as a Minister of State in the Cabinet Office.”

Frost will take up the position on 1 March following roles as Chief Brexit negotiator, National Security Advisor (a post he never took up and didn’t want) and Number 10 advisor on Brexit and International policy.

“This means Dexeu is back,” says one Whitehall observer, referring to the Department for Exiting the European Union, established to, er, Brexit. He means that under different branding, within the cabinet office, Frost will be sovereignty watchman to monitor any mandarin attempts to get Britain too aligned with the EU.

The appointment is another indication that Brexit – the business of leaving the EU or negotiating with it now Britain is out – goes on forever.