Under s. 10(3):
A person infringes a registered trade mark if he uses in the course of trade a sign which
(a)is identical with or similar to the trade mark, and
(b)is used in relation to goods or services which are not similar to those for which the trade mark is registered,
where the trade mark has a reputation in the United Kingdom and the use of the sign, being without due cause, takes unfair advantage of, or is detrimental to, the distinctive character or the repute of the trade mark.
There are so many questions relating to this.
Firstly, are M&S using it? No.
Are they taking "unfair advantage"? Maybe.
But here's an analogy that should answer that:
Site A is a blog that makes money by bringing in organic search traffic for a variety of traffic and from running ads on their pages. They write a post about interflora and that page has an ad for 1-800 flowers. They get visitors from searches relating to Interflora. Is this illegal?
Site B is a business review site that runs ads on their pages. Someone adds a (positive) review of Interflora to their site and, on that page, there's an ad for 1-800 flowers. Is this illegal?
Site C is a search engine. On their page for the search term "Interflora", there's an ad for 1-800 flowers. Is this illegal?
See, to me, I see 3 sites that publish content. So, for that reason, the answer should be the same in all 3 scenarios.
To argue that there's a difference because site C is a "search engine" is, to me, a nonsense. They're all publishers. End of story.
Interflora's argument seems to revolve around google being some sort of special case because it's so popular. I'd be surprised that, if this went to court, they could come up with a sensible argument for that.
Of course, the inability to present a sensible case doesn't mean they can't win.
Steve