OS Highways Converter 1.00 (GeoPackage)

Ordnance Survey Highways Network is the next generation of official British maps.

RouteWare has developed a converter that makes most of the information from this dataset easily available to all of RouteWare's routing products.

Otherwise it can be licensed for €300 from ShareIt.
See further licensing terms in the help file.

Licenses are valid for only 3 years, but includes both the XML and GeoPackage version, if you want to.

It can be downloaded from the download page.