  We perform a novel type of analysis of diffractive deep-inelastic scattering
data, in which the input parton distributions of the Pomeron are parameterised
using the perturbative QCD expressions. In particular, we treat individually
the components of the Pomeron of different size. We are able to describe
simultaneously both the recent ZEUS and H1 diffractive data. In addition to the
usual two-gluon model for the perturbative Pomeron, we allow for the
possibility that it may be made from two sea quarks.
