On Thursday, 4 February 2016 10:24:22 UTC, wrote:

The agreement was that subsets of data were to be made freely available.
Model data is highly processed and regarded as very high commercial value by
the Met Office. Remember back in the late 1990s when radar data were highly
sought after? A compromise was reached in that 5km data would be released..
Nowadays there is 500 metre resolution and higher doppler radar data
available (for internal use). I suspect that the MetO will continue to
release older model data like EURO4 but newer products will be kept under
lock and key.

It's not just the breadth of data but how sporadically disseminated it is. For instance Meteociel now only show T+96, 120 and 144. I'm pretty sure I wrote to the Met Office about this a while back but got the cursory "thanks for your email". Might try again...

Richard