We present photoionization models of the high excitation gas in the Extended Narrow Line Region ( ENLR ) of NGC 1068 .
The ENLR line fluxes have been calculated allowing for attenuation of the central-source ionizing continuum as a function of distance from the centre .
Diffuse continuum emission from low density ENLR gas is included as an important secondary source of ionization .
The observed high excitation emission further than 25 arcsec from the centre of NGC 1068 can be fitted by photoionization models using a central-source luminosity of 3.6 \times 10 ^ { 44 } erg s ^ { -1 } between 10 ^ { 14.6 } and 10 ^ { 18.4 } Hz , with the continuum shape attenuated by nuclear gas with an integrated column density of N _ { h } = 10 ^ { 22 } cm ^ { -2 } .
The reflected soft X-ray continuum from the attenuating gas could be responsible for about 10 % of the observed , resolved circumnuclear soft X-ray continuum extending out to 15 arcsec from the centre ( Wilson et al 1992 ) .