Ah, they have. They got 1m euros (£900,000) from ESA early on, in 2009, then a €10m ($11m, £8m) fund from ESA - then that was enough to unlock £60 million in funding from the UK government (including paying back the ESA funding). They also have an investment from BAE systems after they bought a 20% stake in the company in 2015 for £20.6 million.

This is enough to continue all the way through to large scale tests of the entire SABRE engine core in 2020.

If that works out fine, like all the other tests have so far, then I imagine it might well be taken up by the UK and ESA with a lot more funding in the early 2020s to develop the plane itself.

BTW the Chinese are also working on a hypersonic space plane. It looks a bit like Skylon, and it starts as a turbojet or turbofan, turns into a ramjet, continues later in its flight as a scramjet (air passing through at supersonic speeds), and finally behaves like a rocket to get into orbit.

Chinese idea for a hypersonic plane to fly into orbit from a runway. Looks rather like Skylon but has a scramjet phase with supersonic airflow.

If I understand right (please correct me if I’m wrong), Skylon starts as a turbojet, then continues as a ramjet - so the incoming air is always slowed down to subsonic speeds - then finally continues as a rocket into orbit. So, I think the main difference is that the Chinese idea has an additional scramjet phase??