The French interior minister has claimed the UK government has paid “not one euro" of the £54m promised under a deal to tackle migrants crossing the Channel.
Gerald Darmanin, who visited Calais to inspect efforts to tackle illegal immigration via the Channel, also suggested Britain should "reduce its economic attractiveness" to those making the journey.
He was speaking after Sky News filmed dozens of migrants leaving for the UK as armed police stood by and watched.
Asked by Sky's Europe correspondent Adam Parsons why so many boats were arriving in Britain despite a funding agreement with France to stop the migrants, Mr Darmanin said: "First off, the British government has not paid, for now, what was promised.
"So, for the moment, there is not a euro that has been paid by the British government following the deal - more or less - that we negotiated with (Home Secretary) Priti Patel.
"The English are people of honour, so I am certain that it is an accounting delay.
"Secondly, it has been more than 20 years since France has overseen the border for our British friends. We have succeeded in largely reducing the pressure from immigration. And what we see in Calais and Dunkirk now is nothing like what we saw five or six years ago."
He said the French government had dismantled camps as well as increased the numbers of police and installed fortifications to protect the border.
He added: "We need Great Britain to reduce its economic attractiveness for migrants who want to work in the UK."
A Home Office spokesman said: "French and UK officials continue to work together on the final funding arrangements, which form part of the bilateral agreement.
"We maintain regular contact with France on this work at an operational and policy level.
"This year record numbers of people have put their lives in the hands of ruthless people smugglers and risked perilous channel crossings from French beaches.
"Joint cooperation with the French has led to nearly 300 arrests, 65 convictions and prevented more than 13,500 crossings. But with hundreds still risking their lives and making the crossing, all sides must do more."
Ms Patel told the Tory Party conference last week that France "is a safe country" and she would "turn back the boats".
But this did not stop more migrants successfully crossing the Channel at the weekend, with Border Force and RNLI vessels bringing them to safety in Dover and Dungeness in Kent.
Speaking to Sky News, UK In A Changing Europe economist Jonathan Portes said: "I think there clearly has been a deterioration in the UK-France relationship on this score, as well as on many other fronts, whether that ranges from the submarine deal with Australia through to the issues with French fishermen who complained about being shut out of their historical fishing waters near the Channel Islands.
"It's difficult to know whether this is just one isolated incident or whether this reflects this broader deterioration in UK-French relations. Now, to the extent it's the latter, that clearly is very damaging for the UK and for France."
Alp Mehmet, chairman of Migration Watch UK, said the French police are not making any attempt to stop people from crossing the Channel.
He told Sky News: "They are not doing anything to challenge those coming into France at the point of entry. The EU is doing absolutely nothing to stop them from coming in.
"They are coming from a safe country [France] and that country is doing absolutely nothing to help them stay in that country."
French fisheries workers claim they have been "deceived" by the British government over fishing licence applications and have called on the European Commission to take "retaliatory measures".
And France has again threatened to cut the UK off from energy supplies if the terms of the Brexit deal aren't stuck to.
The country's Europe minister, Clement Beaune, said the agreement had to be "implemented fully" and - should it not be - then "we will take European or national measures to exert pressure on the UK".