PARIS — Either the U.K. changes its tune or the EU won't change the Brexit deadline, a senior French official warned Wednesday.

Only a "political change" in Britain, creating the possibility of a "different dialogue," would justify an extension of the October 31 Brexit deadline, France's state secretary for European affairs, Amélie de Montchalin, told a parliamentary hearing on Wednesday.

"If new elections, if there’s a new referendum, if there is a political change that leads us to think that we could have a different dialogue than the one we are currently having, an extension request can be discussed," de Montchalin told a National Assembly hearing.

"But giving more time in the same exact conditions we see, it doesn’t give lots of hope that things will go differently," she said. "It’s not three more months that will resolve the complexity of the problem. On the other hand, what can help us is if we have other interlocutors, or that they carry a more aligned position between what the parliament says, what the population thinks and what the government says."

The Brexit back-and-forth is coming down to the wire, with London and Brussels pessimistic about prospects for a deal just one week before a crucial European Council leaders' summit.

In Brussels, EU officials and diplomats are bracing for the possibility that French President Emmanuel Macron will take a hardline stance against any further Brexit delay given the continuing political chaos in London — despite the repeated insistence of other EU leaders that they would never force a no-deal outcome if any chance remained for a deal.

It was Macron who, almost single-handedly, pressured his fellow leaders at a summit in April into offering the U.K. only a short-term extension until October 31, while others, including European Council President Donald Tusk, wanted a long delay of a year or more.

Macron has indicated that he will make an assessment by the end of this week on the likelihood of reaching a deal based on a proposal put forward by U.K. Prime Minister Boris Johnson. Other EU leaders have said much of the proposal is not workable, including the bloc's chief Brexit negotiator, Michel Barnier, who told the European Parliament on Wednesday: "At this particular point, we are not really in a position where we are able to find an agreement."

At the hearing in Paris on Wednesday, de Montchalin prefaced her remarks by noting that the French position on a delay effectively was the same as it was six months ago, when the U.K. last needed and requested an extension. Tusk, Macron and other leaders had urged the U.K. to make good use of the extra time.

But while Theresa May resigned in the interim, following a third rejection of the Withdrawal Agreement by the U.K. parliament, the overall political paralysis has not changed. Indeed, the dynamic between Brussels and London appeared to worsen as Johnson took control at No. 10 Downing Street and stocked his government with ardent supporters of a hard Brexit.

For many in Brussels, Macron remains the biggest wildcard.

While the EU's official position is that it is still trying to understand all of the technical aspects of Johnson's proposal — and still remains very open to a deal — most officials and diplomats have concluded that an extension is virtually unavoidable, and that the only alternative is a slight risk that Johnson somehow finds a way to defy his parliament and force a no-deal departure.

But for many in Brussels, Macron remains the biggest wildcard. That is largely because France is viewed as having perhaps the most to gain politically from the U.K.'s departure.

Not only would a British exit end years of sparring between London and Paris over EU policy, it would also catapult France into a position of unmatched prominence in the bloc: as the only EU member country with a seat on the United Nations Security Council, and the only one with an arsenal of nuclear weapons.

While no one disputes the inescapable economic harm of forcing the U.K. out, even some EU officials concede that there is merit in getting the whole business over with sooner rather than later — especially if it seems inevitable that a deal can never be reached.

“I wouldn’t be too sure of what will be France’s line, not in this scenario,” a senior EU diplomat said.

A senior EU official called the departure of Britain “a unique opportunity" for France.

"They will be the one left with a finger on a nuclear button and a U.N. seat," the official said.

With German Chancellor Angela Merkel now in the twilight of her career, many EU officials say the U.K.'s departure would leave Macron in a position to wield greater influence.

Macron is understood to be genuinely unhappy about the way Brexit has dragged on and is now threatening to distract from the start of the new European Commission, to be led by former German Defense Minister Ursula von der Leyen.

The new Commission is set to take office on November 1 and Macron is eager to see the new EU leadership get a fast start on an aggressive agenda, particularly in moving to combat climate change.

At the same time, a no-deal exit by the U.K., on the very first day the Commission starts work, would require von der Leyen and her new team to immediately go into emergency management mode. For that reason, some officials expect Macron could be persuaded to grant one more short extension, simply to let the new team find its footing — and that, in fact, the French president is merely playing bad cop.

"It's just a carrot-and-stick strategy where the French play the stick,” a second EU official said.

The second official said Berlin is playing the role of carrot — a potentially alarming prospect for London given the unhappy phone call on Tuesday between Johnson and Merkel that prompted a British official to conclude a Brexit deal could never be reached.