The twin messages from the EU to Westminster could not have been more blunt - even as British MPs were again voting on where they believed Brexit should now head.
Message one, your new unilateral tariff regime - including a special regime on the island of Ireland - is in breach of World Trade Organisation (WTO) rules. Message two, your MPs can vote all they like about Brexit extra-time - it's up to the EU member states to decide, by unanimous vote, if there will be an extension and what its duration might be.
And there was also a double-barrelled warning from EU kingpins Jean-Claude Juncker and Donald Tusk that a longer extension will involve having to organise European Parliament elections in the UK on Thursday, May 23.
The UK's early morning announcement on trade tariffs, in the real likelihood of a no-deal Brexit, rightly horrified Irish farmers and food processors especially. But the EU Commission's response was rather swift and published by lunchtime.
The policy-guiding commission instantly raised a red flag about planned no-deal trading arrangements for the island of Ireland. The commission also said London's plan for UK-EU trade elsewhere also "raises concerns".
The commission added that, rather than scrapping most tariffs, as the UK planned to do, the EU would levy standard duties on British imports in line with WTO rules.
"This is essential for the EU in order to remain a reliable trading partner to the rest of the world," a strongly worded EU Commission statement said. This was a clear elbow in the ribs for the UK, suggesting it may begin its post-EU existence as a less reliable global trading partner.
Some observers saw the UK tariffs move as an attempt to pressurise the Irish Government ahead of an EU leaders' summit next week. That's when the leaders will decide on an extension to the Brexit timetable and what duration that might be.
Sources in Dublin downplayed that scenario.
Speaking from Brussels, Irish Commissioner Phil Hogan saw the UK tariff announcements as an attempt to divert media attention from the Westminster confusion.
Commissioner Hogan, a key person in deciding farmer and agribusiness compensation, also appealed for calm ahead of continued change.
For Taoiseach Leo Varadkar, in Washington, the situation was replete with irony. The radical upholders of Brexit, and opponents of Theresa May's deal, based their stance on the North not getting different treatment from England, Scotland and Wales. But now London's first major announcement for a post-Brexit world had done just that.
It's a memo to the DUP - your belligerence may well deliver the very thing you set out to avoid.
Last night UK MPs voted to reject a no-deal Brexit. Tonight they will vote on an extension.
But reality is that these matters are now largely to be decided by the EU leaders next Thursday and Friday when they meet in Brussels.
Across Europe there was a strong questioning about the value of a Brexit extension. A short delay until before the European Parliament elections appears the best offer. Anything else requires a big change of heart by the UK and a clear plan.