Read this morning’s headlines, and you’d be forgiven for thinking the highest-stakes Brexit meetings this month are taking place in Berlin and Paris – as Boris Johnson trails round European capitals meeting his German and French counterparts. But this is all for show.

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Angela Merkel and Emmanuel Macron don’t need to meet Johnson in person to hear about his hardline demand that the backstop be altogether removed from the withdrawal agreement. And no amount of cordiality from Germany’s chancellor changes the fundamentals of the standoff: Europe will not drop the backstop unless there is a practical, workable alternative on the table – which there isn’t. The impasse continues.

Far more important are the meetings that will be happening in Westminster next week, as MPs start to return from their summer breaks. Jeremy Corbyn yesterday wrote to the leaders of the opposition parties, Conservative Brexit rebels and independent MPs to invite them take part in talks next Tuesday on how best to block no deal. These are the conversations that all ears in Brussels will be listening out for.

Johnson asserted to Merkel this week that parliament simply couldn’t block a no-deal Brexit. But he isn’t in a position to offer those assurances: that’s up to parliament, not the prime minister. And it’s those conversations between opposition MPs that provide the best chance of avoiding Britain crashing out without a deal on 31 October. The stakes couldn’t be higher.

These cross-party talks are long overdue. Thus far the attempts to take no deal off the table have been led mainly by backbenchers, and the failure to agree on a constructive way forwards means that MPs haven’t yet been able to go beyond simply expressing their will that no deal should not happen. They haven’t taken any definition action to make that a reality. There simply hasn’t been the coordination that would be required between those party leaders who all want the same thing: to stop a no-deal Brexit.

It may have come late in the day, but Corbyn has now offered a procedurally failsafe route to block no deal, should other MPs choose to back it. MPs would vote against the government in a vote of no confidence, and Corbyn would form a temporary government, with the support of opposition parties and Conservative rebels, whose sole purpose would be securing an article 50 extension, then triggering a general election in which Labour would campaign for a referendum with a remain option.

The problem is that Eurosceptic Corbyn is an unlikely leader for a remain resistance: he is distrusted by pro-Europeans such as Jo Swinson, who feel he has been dragged to this position kicking and screaming, and too many MPs who want to avoid no deal say they could never put him in government, even temporarily. But the fact is he’s the leader of the main opposition party, with the best chance of bringing the greatest number of MPs behind him as the anti-no deal temporary prime minister. Swinson and others may not trust his motives – and believe he’s only made the offer to escape blame if and when no deal happens – but if stopping no deal matters above all else, why not call his bluff? It’s hard to see sufficient numbers of Labour MPs getting behind Swinson’s suggestion of a backbencher as temporary prime minister, even if it’s someone who comes from their own ranks, such as Harriet Harman.

This impasse among remainers means that a temporary government to block no deal feels politically unlikely. Conservative rebels such as Dominic Grieve are working on an alternative plan, which would see parliament take over the legislative agenda in September and pass a bill to mandate Johnson to ask for an extension to article 50. This feels more likely politically, although there are questions about whether it could work procedurally, even with a sympathetic Speaker. If it were to happen, Johnson would likely trigger a general election in order to get a mandate for no deal. If none of that works, there’s also a last nuclear option: parliament could vote to revoke article 50 in the days leading up to 31 October.

Johnson is wrong that parliament can’t block no deal. As much as he might wish it away, we still live in a parliamentary democracy, in which parliament is sovereign. But we remain stuck in the position that while there’s a majority of MPs who don’t want no deal to happen, they can’t agree on the constructive action that would be needed to stop it.

Will they find it within them to work across party lines – and with some age-old political enemies – to do so? The jury is still out. So it’s Westminster where all the important action is happening this August, not in those continental capitals where leaders are politely rehashing for Johnson the same argument that they had with Theresa May for the past two years.

• Sonia Sodha is a Guardian columnist