The Sabre engine is being developed for the Skylon spaceplane, which designers say is capable of travelling 19,000 mph and reaching the Earth's stratosphere in 15 minutes.

It could accelerate Mach 5 aircrafts to five times the speed of sound and if adopted by passenger jets could cut the flight from the UK to Australia by four hours.

The funding boost from the UK Space Agency for Reaction Engines, the Oxford-based company behind Sabre, will pave the way for building a full-scale prototype.

Science minister David Willetts said: "By supporting this breakthrough technology we are giving the UK a leading position in a growing market of new generation launchers and removing one of the main barriers to the growth of commercial activity in space.

"Sabre has the potential to completely transform how we currently access space whilst further boosting the burgeoning UK space sector."

The investment follows successful tests of the technology involving the rapid cooling of air entering the engine at hypersonic speed.

The development of the rocket engine could also lead to the creation of 21,000 engineering and manufacturing jobs.

Alan Bond, who founded Reaction Engines, said: "This significant investment in British high-tech technology is a fantastic shot in the arm for the UK aerospace and space sectors, as well as the broader economy.