"Get Brexit done": that was the slogan that helped deliver a general election triumph for Boris Johnson in 2019. Now it's being thrown back at him from a perhaps unexpected quarter - European Commission vice president Maros Sefcovic.
Mr Sefcovic issued the retort during a speech at Bloomberg's London HQ that resonated with the torturous history of Britain's departure from the EU - it was the venue of David Cameron's speech in 2013 pledging a referendum on membership of the bloc.
The commissioner said UK legislation designed to tear up parts of the protocol, which governs Northern Ireland's post-Brexit trading arrangements, simply "would not work".
He also warned that the "shadow being cast" by the row would make Brussels more vigilant about continuing to allow British businesses access to financial services, data and certain food markets.
Ending so-called "mutual recognition" of regulations in those sectors could become a possibility as a result of the UK changing its standards, said Mr Sefcovic, adding that Brussels "will be watching development closely".
The protocol was devised in order to prevent the return of a hard border between Northern Ireland and the Republic of Ireland.
But a consequence is that goods exported to Northern Ireland from Great Britain are subject to customs checks, outraging unionists who are refusing to join power sharing until this changes.
Britain has rejected proposals by the EU to resolve the impasse.
"We indeed find ourselves in a difficult situation, which will most certainly not simply disappear," Mr Sefcovic said.
"You may not hear this often from a European Commissioner, but it is high time we got Brexit done."