The Telegraph has a screen grab as evidence that it did trend:
The #welovethenhs hashtag was started (I haven’t yet tracked down who by) to help defend the National Health Service from the scurrilous attacks that are being launched on it by right-wing Republicans in the USA. President Obama has made healthcare reform a central pillar of his presidency, to right the many wrongs and injustices of the US healthcare system, which penalises the most vulnerable and rewards the most privileged â€“ the exact opposite of what most people would expect a healthcare system to do.
Most of the #welovethenhs tweets include short (140 character!) stories about people’s personal experiences of the NHS.
There is even a ‘Twibbon’ that will overlay a welovethenhs graphic over your Twitter avatar to show you’re supporting the campaign.
Update, it’s still trending on Twitscoop (and by a LOT!):
but not on Twitter or Twitter Search: