In 2002, a new laser facility, Vulcan Petawatt, is being brought on line to users. With a specification of 1PW ( l0^15Watt) and a target irradiance in excess of l0^21W.cm-2, Vulcan Petawatt will be the most powerful laser facility in the world. Fed with laser pulses from the CLRC's Vulcan laser, the new facility will give users access to unexplored regimes of physics where relativity dominates the interaction of the laser light with the target. Indicative experiments include acceleration of particles to ultra-high energy, generation of 100MG magnetic fields and the study of matter under extreme conditions of temperature (10 million degrees) and pressures (>100Mbar). We propose a total programme of EU access of 18 weeks to the Vulcan Petawatt Interaction Facility distributed approximately evenly over the full period of the project. We estimate that 24 individual researchers will benefit from this programme with further researchers involved in theoretical support and data analysis.