Imagine that Britain signs a treaty with France agreeing to take its unwanted migrants for cash payment; that France suggests sending lawyers to this country to ensure the British courts treat deportees properly; and that the French national assembly passes a law declaring Britain to be a safe country for its cast-off migrants.
What do we suppose would be the response of the Rishi Sunaks and James Cleverlys of this world (not to mention the Suella Bravermans, Robert Jenricks and Matthew Goodwins)? There would (rightly) be spitting fury. There would be outraged talk about the loss of British sovereignty and choleric questioning of why France could not deal with its own problems rather than dump them on Britain.