As if Conservative donors were not resentful enough – where they haven’t already complied with Boris Johnson’s injunction to fuck off – it is now clear, thanks to the Treasury secretary, Liz Truss, by what a prodigious margin some of them must have overpaid for a basic minister experience. It’s ages since a party chairman quoted £250,000 as the starting price to get near David Cameron.

A photograph posted on Truss’s Instagram account last week showed six female cabinet members and the prime minister assembled beside a wealthy woman of Russian origin. Lubov Chernukhin had gifted herself their presence (in an auction at the latest Black and White Tory fundraiser) for £135,000: ie, less than £20,000 apiece for hours of proximity to Karen Bradley (Northern Ireland secretary), Baroness Evans (leader of the Lords), Caroline Nokes (immigration), Amber Rudd, Andrea Leadsom, Truss and – smiling alongside Mrs C – Theresa May.

Liz Truss #girlpower. Photograph: Peter Nicholls/Reuters

So, when you factor in dinner at the Goring luxury hotel (£64 a head excl wine and extras) and the promotional value (incalculable) of the photo with #girlpower added by Liz Truss #StupidSpice – not so much good value as probably the most careless political giveaway since the same Mrs C bought a classic Cameron and Johnson adventure, with tennis, for £160,000. A “Scones and Sass” Ruth Davidson meal experience later cost her £20,000.

In fact, it may be some comfort to Gavin Williamson, while he monitors his children’s health, to recall that Mrs Chernukhin (whose husband once worked for Vladimir Putin) offered £30,000 for his own exclusive defence secretary dining event. If, by unkind coincidence, she booked his services shortly before Russian agents poisoned the Skripals, Williamson could reasonably retort that his fundraiser did not, in contrast to the Goring hotel novelty hen night, immediately follow headlines about a savage “crackdown” on Russian influence in UK politics.

There can clearly be no suggestion that Mrs Chernukhin is anything but a fine Russian-turned-British citizen with a passion for UK politics – or politicians, anyway – which puts many nationals to shame. But her very devotion to the Conservative cause surely means she would have understood if, for reasons relating to appearances, her new cabinet BFFs had concocted some excuse – a poorly pet, a particularly busy election, even a national emergency unprecedented since the Second World War? – to postpone, preferably forever, their girls’ night out.

This further confirmation of the Conservative party’s tragic condition would also delight Vladimir Putin

Yes, May and her ministers would have missed a marvellous opportunity to find out who exactly Mrs C is, beyond the generous wife of an incalculably wealthy Russian expat, Vladimir Chernukhin – she must be fascinating on his acquisition of British residency and that time he paid a reported £72m for a massive building he then had to sell – but would those insights, plus her loyalty, quite compensate for the political fallout if nobody kept an eye on Liz Truss #girlpower?

Even if Mrs Chernukhin were, in fact, the Moscow diaspora’s answer to Dorothy Parker – only richer, blonder and with a rare talent to unite leave/remain adversaries – this further confirmation of the Conservative party’s tragic condition would, as she would surely appreciate, also delight her husband’s reported enemy, Putin. The latter’s spokesman once jeered that Britain only matters, now, to “the oligarchs who have bought Chelsea”.

Anyway, there would have been no need, given the wealth of available excuses, for the women to have embarrassed Mrs Chernukhin with an allusion to a court judgment that might bother anyone more old fashioned than Liz Truss #girlpower. Concluding an immensely protracted, hugely unedifying dispute between Mrs Chernukhin’s husband and his former business partner (and former host to George Osborne), Oleg Deripaska, and – bear with me – Mr Chernukhin’s ex-girlfriend Lolita Danilina (since aligned with Deripaska), Mr Justice Teare recently ruled in the high court in favour of Mr Chernukhin.

Who, it might be asked, other than Deripaska, Danilina and the Chernukhins, plus the assorted lawyers, estate agents, wealth managers and other hangers-on they enrich, gives a solitary toss about this latest judicial contribution to order among oligarchs? Anyone?

The judge’s preamble is a different matter and not only because, being drily hilarious, it deserves a far wider audience than the (surviving) residents of Londongrad alone can supply.

Great caution is required before accepting Lubov Chernukhin's evidence Mr Justice Teare, in the high court

Even allowing for the vagaries of human memory, oligarch culture and the occasional language difficulty, Mr Justice Teare finds “the depressing fact is that there was good reason to doubt the honesty of each of the principal actors in this case”.

Of the victorious Mr Chernukhin he says: “As with Mrs Danilina and Mr Deripaska, I determined I should exercise great caution before accepting his evidence.” And what of Mrs Chernukhin: witness in this case; patron of Cameron, Johnson, Brandon Lewis, Williamson, Davidson and now Bradley, Evans, Nokes, Rudd, Leadsom, Truss and May (apologies to any Tories omitted)? The judge considers “she was not being frank with the court”, concluding: “Great caution is required before accepting her evidence.”

If – we’d have to check with Truss – #girlpower requires us to rally, with hugs, around Russian Spice, against harsh Mr Justice Teare, it is difficult to see what, even after her £1m in donations, persuaded May and company to take the reputational risk of an evening with an unreliable witness, the wife of another unreliable witness once close to Putin, whose wealth remains the subject of conjecture. In fact, other than her marriage and love of MP experiences, the judge’s summary appears to be one of the very few things we know for sure about Lubov Chernukhin.

Were May, Leadsom, Rudd et al entirely uninformed about this episode? Indifferent? Or did the all-women gathering promise, of its exceptional nature, to transcend all such worldly, oligarchyish concerns? Bad luck.

• Catherine Bennett is an Observer columnist