What type of spider is this?

Oh that sounds harmless is it? Someone at work told me its a poisonous false widow spider but surely thats not it?

As far as I understand it, False Widows (there are more than 1 type in the UK) are called that simply because they look like or are from the same family as the infamous Black Widow. It does not imply they are anywhere near as dangerous even though some are non-native invasive species. Having said that, I think your colleague is wrong anyway and it isn't any of the False Widows.
It isn't easy to tell from the photo (and my ID ability) but I'm not convinced it's a Walnut Orb Weaver either. My guess is that it is either a Common Orb Weaver (Metallina species) or a Furrow Orb Weaver (Larinioides species). Both are common and relatively harmless (as is the Walnut Orb Weaver).

I'm no expert either so you might be right.
The reason I suggested alternatives is because I am not convinced the shape of the abdomen is right for a typical walnut orb and, although it is not beyond the realms of possibility, it would seem to be a very light example for one of those from what I have seen. Given that all are common and highly variable I personally wouldn't rule any of them out just yet!

This is a silver-sided sector spider, or a missing sector orb weaver

Definitely of the Orb Spider family, we have a few similar, and I've ID'd those as garden cross, but I could be wrong.

The problem with Google (and probably Bing and many others as well) is money shouts the loudest with searches, and their trending searches are either a bad joke, or a very sad sign of the times....

Any web related searches I undertake are always taken with a big pinch of salt, I use books first, then fine tune as required on the web. Also, you get those who innocently mistakenly ID something, and a search can bring it up. Sometime back I'd mistakenly ID'd a bird on here, and that came up in a search. I will confess, I did fine tune my Google search, but not by much because I wanted to prove to myself how accurate these searches can be.