European parliamentary leaders insisted Thursday there can be no Brexit withdrawal agreement without the "Irish backstop" clause that Britain's Prime Minister Boris Johnson

has demanded be stripped from any accord.

With a chaotic no-deal Brexit on October 31 now looking more and more likely, officials in Brussels increasingly accuse Johnson of conducting a sham negotiation as political cover while planning to crash out without an accord.

Next week, MEPs will vote in the Strasbourg parliament on a motion to reaffirm and reinforce the European negotiating stance -- and seek to place the blame for the stalemate in the talks firmly across the Channel in London.

"The resolution says that if there is a no-deal departure, then that is entirely the responsibility of the United Kingdom," he added at a news conference after senior MEPs were briefed by EU Brexit negotiator Michel Barnier.

Barnier told AFP that he had received no plausible proposal from Britain as to how the backstop -- a measure which sees Britain remain in the EU customs union until a way is found to keep the Irish border open after Brexit -- could be replaced.

"Regarding the talks we are still ready to examine objectively any concrete and legally operable proposals from the UK," he told reporters.

Johnson's chief Brexit adviser, diplomat David Frost, was in Brussels on Wednesday and will return on Friday for "technical talks" with Barnier's team, but Number 10 continues to insist that the backstop must go before a deal is signed.

"The UK presented ideas in the areas of customs and manufactured goods and we had further exchanges on the political declaration," a UK spokesman said, as Britain continues to push alternative technical measures to govern border traffic.

Johnson insists his goal is to reach a new withdrawal deal that would lay the groundwork for negotiating a future free trade agreement with Brussels, but that Britain must leave the bloc at the end of next month, come what may.

Many in Brussels doubt his sincerity and argue that -- since Johnson has lost his House of Commons majority and failed to convince the UK parliament to back a snap election -- he may not be able to get any deal past his own MPs.

Johnson nevertheless says progress is being made but, asked whether this is true, Green parliamentary leader Philippe Lamberts, a member of the Brexit steering committee, said: "No, it's not my sense but I guess he has to say that."

- Special treatment -

"He has to give the impression that he's negotiating in good faith. I think his whole plan is to take the UK out of the European Union without any deal but at the same time being in a position to blame the European Union for inflexibility," Lamberts said.

"He must project the image of someone who negotiates in good faith, who wants a deal etc, so that if there is no deal obviously it can't be him, it must be the others."

One idea that has been circulating in press reports, and was cited by Sassoli as possible, is to return to Barnier's original concept of the backstop as a measure that would only apply to Northern Ireland, while England, Scotland and Wales leave the customs union.

Downing Street insists that Britain will not seek this -- and Barnier says he has received no proposals at all -- but Lamberts and Sassoli suggested that it might be welcomed in Brussels.

"I think it is the most sensible option because it allows the mainland UK to still have full autonomy in terms of regulations and customs and yet it is a special treatment for Northern Ireland," Lamberts told reporters before meeting Barnier.

"That to me, seen from my perspective is a lesser difficulty than having the entire United Kingdom in such an arrangement."afp