The Department for Digital, Culture, Media & Sport had a target "to provide access to basic broadband (2Mbps) for all from December 2015" which they failed to reach and had to revise. Until last month I was only getting 1.0Mbps which is totally not acceptable in 2017 UK.
"A subsidised broadband installation is now available if you cannot access an affordable broadband service with a speed of at least 2 Mb per second." They really don't want to give you a subsidy; I found that after lots of loud complaining the magical Openreach unicorn fairy did a surprise upgrade of my local cabinet instead.
If you are looking for evidence of your slow speed I can recommend going through an EE broadband online application then screenshotting, as EE seem to be the most conservative in promising what your speed would be.