I am not sure if this is 100% new in the UK or not. But it appears that from a Search Engine Watch Forums thread that moderator EvilGreenMonkey started, Google has now implemented Click-To-Call features in the UK.
A search on jet2 at Google.co.uk brings up this ad.
If you click on the green phone icon, it opens the ad up to enter your phone number;
I am not sure if they launched this in the UK before, but I believe they haven't. This has been launched in the US a while back. Hat tip to Sami Kasap.
Forum discussion at Search Engine Watch Forums.