[Trevor Australis]

Be aware that David Austin roses are all subject to PVR (plant variety rights) and strictly speaking it in illegal to propagate them without a license from his business. From time to time his reps travel to Australia to audit the propagation of his rose vars. here and people have been prosecuted, and others threatened with it. 'Back-yard' propagators are included. Closer to the UK his  'inspectors' might make more frequent surveys. As I understand things it is not even legal to grow Austin roses from cuttings taken from your own garden to grow in your own garden. Comments anyone?

[Alisdair]

In the UK these rights are known instead as Plant Breeders' Rights (PBR), and specifically do not cover private use.
Generally speaking, each country has its own legislation covering such rights. There is also a European Union system, covering the whole EU, run by the Community Plant Variety Office (CPVO).
To complicate matters, plants can also be patented, nationally or EU-wide. Most David Austin roses are patented. Again in the UK (and I think the EU), a plant patent does not cover private use, but I don't know about other countries' rules.