Partners can be a fickle bunch. Just look at Ashurst: the firm's desire to secure a US merger dates back so far that it's hard to think of a UK firm – legacy SJ Berwin or Norton Rose aside – more frequently linked with potential partners across the Atlantic or with more public failed combination attempts behind it. Even the firm's tie-up with Blake Dawson – now Ashurst Australia – gave both firms a controversial get-out clause in the event that the UK firm were to find a US suitor it would prefer to share a bed with.

And yet, when then senior partner Charlie Geffen – backed by a handful of lieutenants – last year presented Sidley Austin to the board as a possible merger option, the firm decided to walk away not only from the talks but ultimately from Geffen himself. Discussions with Sidley ended at a very early stage, while Geffen went on to lose the chairman election to Ben Tidswell.

Clearly, with combined revenues of around