And John Lewis is clearly a piece of business loved and nurtured by Lowe. OK, the agency hasn't got too much else to love - its client list is a shadow of its former self. And with new business rarer than a Lowe chief executive, holding on to existing clients is paramount.
But John Lewis is in change mode. Craig Inglis, who joined in February as the head of brand communications from Virgin Trains, says he's looking at costs. Hmmm. How many times will we be writing about clients doing that over the coming year?
So Inglis says that "as we are carefully evaluating all our costs in the current economic climate, we feel that this is the right time to put our account out for review to be absolutely confident that we have the best possible solution for our partners and the business as a whole".
In which case, it's interesting to note that the company doesn't feel the need to put its direct marketing agency (Kitcatt Nohr Alexander Shaw) or its media agency (Manning Gottlieb OMD) through a similar review process.
Still, Inglis does admit "our relationship with Lowe has been a happy one and they have delivered some outstanding work for us". But is Lowe, rock bottom, the agency it was even in 2006 when John Lewis appointed it? Well, no.
Mind you, even back then, the appointment was accompanied by a headline in Campaign: "Lowe London in win shock." We wrote that despite turmoil at the agency - which was at the time without a chief executive - the win was testament to the lure of a strong creative director: Ed Morris, who had just been locked in to Lowe with a superstar salary package. "That now seems to be money well spent," Campaign said when John Lewis handed over its business.
Ironically, Lowe is again without a chief executive, Morris' eye-watering contract has just been renegotiated and the agency is once again the subject of much gossip and speculation. You've only got to read Morris' own statement following news of the John Lewis review to sense the mood there: "Fuelled by my complete commitment to the agency, John Lewis and the fantastic work we are capable of doing together, I will be leading the charge." Clearly Morris is as aware of the rumours about his future as we all are.
And as a further mark of how desperate the market thinks Lowe is, this week there's been wild talk that the network might even ditch the Lowe brand in favour of reviving the Lintas name.
Coming a week after Fernando Vega Olmos - beloved, apparently, by Lowe's Unilever client - quit as the chairman of Lowe Latina to join JWT (page 13), Lowe must be reeling.
Despite all of this, the agency still has the chance to turn things round. Its creative reputation, although not what it once was, is still better than that of some bigger, healthier agencies. And there remains goodwill in the market towards the Lowe brand. But surely the time for turnaround is running out.
So Baroness Peta Buscombe is quitting the Advertising Association for the Press Complaints Commission. Really, it's not so surprising. In a short time, she has proved herself to be one of the AA's best ever chiefs and has taken up the industry's cause with a rare energy at one of the most important times in its history.
She will be missed, not least because she leaves the job far from done. Finding a worthy replacement is a matter of real urgency if the advertising industry is to maintain the momentum Buscombe has kick-started.