  We propose a 4+1-dimensional action that is a candidate for realising a
standard-model-like effective theory for fields dynamically localised to a
domain-wall brane. Our construction is based in part on the conjecture that the
Dvali-Shifman mechanism for dynamically localising gauge bosons works correctly
in 4+1-d. Assuming this to be so, we require the gauge symmetry to be SU(5)in
the bulk, spontaneously breaking to SU(3)xSU(2)xU(1) inside the domain wall,
thus dynamically localising the standard model gauge bosons provided that the
SU(5) theory in the bulk exhibits confinement. The wall is created jointly by a
real singlet-Higgs field eta configured as a kink, and an SU(5) adjoint-Higgs
field chi that takes nonzero values inside the wall. Chiral 3+1-dimensional
quarks and leptons are confined and split along the bulk direction via their
Yukawa couplings to eta and chi. The Higgs doublet and its colour triplet SU(5)
partner are similarly localised and split. The splittings suppress
coloured-Higgs-induced proton decay and, because of the different localisation
profiles, the usual SU(5) mass relation m_e = m_d does not arise. Localised
gravity is generated via the Randall-Sundrum alternative to compactification.
