According to Debrett’s, the arbiters of etiquette since 1769: “Visitors, like fish, stink in three days.” Given this, it’s difficult to imagine what Ecuador’s London embassy smells like, more than five-and-a-half years after Julian Assange moved himself into the confines of the small flat in Knightsbridge, just across the road from Harrods.

Ecuador’s foreign minister has said the country is seeking “mediation” to resolve the “unsustainable” situation of Assange’s residency in the embassy, which ostensibly centres around Ecuador offering the WikiLeaks founder political asylum against possible prosecution in the United States. Assange took up post in the embassy a few weeks after interviewing the country’s then president, Rafael Correa, on his Russia Today television show. Correa made an apparently casual offer of asylum during a discussion of Assange’s extradition case with Sweden, following accusations of rape and sexual assault by two women.

Assange pursued his extradition case right through the British legal system, aided by some of the country’s leading human rights barristers, and extradition was eventually granted – denying Assange’s appeal – by the UK supreme court.

It was at precisely this point – when extradition to Sweden to face potential prosecution in his rape case seemed certain – that Assange, concerned about potential US prosecution over WikiLeaks, fled to the embassy.

Given Assange and Ecuador have spent more than five years saying his asylum was unrelated to the Swedish case, even Sweden’s decision last year to abandon the case – citing no chance of conviction after Assange’s flight from justice – was not enough to give any chance of closure. If Assange had announced plans to leave the embassy at that stage, it would be clear his story for the previous five years had not been entirely truthful.

Ecuador’s decision to seek mediation now is, on the surface, quite puzzling: it didn’t make that announcement when there was a genuine development in Assange’s Swedish case, nor did it do so when Donald Trump became the president, last year.

There is no public criminal case against Assange or WikiLeaks in the US, though Assange frequently says there is evidence of sealed indictments against him and his associates, and there have been publicly disclosed surveillance warrants against WikiLeaks staff, as well as FBI interest in Assange and his current and former co-workers (including me, as I worked with WikiLeaks for a few months in 2010 and 2011). There is no real reason to believe anything has changed with Assange’s situation in the US.

What has changed is Assange’s value to Ecuador as a political symbol. Internal documents revealed that relations between embassy staff and Ecuador’s most famous asylee were fraught. Security staff were filing minute by minute reports of Assange’s movements to Ecuador’s intelligence agency. Last year, these tensions came to the fore as Assange was publicly reprimanded by Ecuadorian officials for interfering in the US election process – by publishing hacked emails from the DNC and Clinton campaign – while claiming asylum. Assange’s internet connection was eventually cut off by Ecuador, to his visible public rage.

When Ecuador first gave asylum to Assange, he was still a hero to many on the liberal left, and to many opponents of “US imperialism”. Today, most of those who still support Assange are hard-right nationalists – with many seeing him as a supporter of the style of politics of both Trump and Vladimir Putin. Assange is not the political icon he used to be.

This is perhaps what’s behind Ecuador trying to seek a way to end the standoff. Assange’s effect on foreign and diplomatic relations surely outweighs much of what Ecuador’s own diplomatic corps would like to do.

The problem for both sides is that neither wants to lose face: Assange wants to be a symbol of resistance against an overreaching US state, and does not want to admit his asylum was about his personal actions and not those of WikiLeaks. Ecuador does not want to suggest it made a mistake in granting Assange asylum.

Their problem is a simple one, though: what is there to mediate between the UK and Ecuador on Assange? Assange’s case in Britain is not a political one, it’s a matter of simple law. Assange was arrested on a European arrest warrant and eventually granted bail – then fought his extradition case right the way to the supreme court.

Following Sweden’s decision to abandon its attempts to extradite Assange, all that he faces in the UK is the relatively straightforward matter of breaching bail – a minor offence, but not one suitable for political negotiation. Ecuador’s “mediation” pitch to the UK amounts simply to asking them to ignore UK law – it’s not a strong ask.

Assange should not face prosecution in the US in connection with WikiLeaks publishing activities – it would go against constitutional principles of free expression, and damage the media’s ability to hold power to account. The US would dispute any such prosecution would be political, though – the country pursued New York Times journalist Jim Risen through the courts for some time – and the UK still has an open police investigation into journalists who worked on the Edward Snowden leaks. Given Assange’s recent leaks benefited the current US president, what case is there to make that prosecution would be political?

Assange does not want to be trapped in Ecuador’s embassy, and his hosts do not want him there. Their problem is that what’s keeping him trapped there is not so much the iniquitous actions of world powers, but pride. Perhaps it’s not Ecuador and the UK that need a mediator, but rather Ecuador and Assange.

• James Ball is a former Guardian special projects editor