Borders taken from Image:2005UKElectionMap.svg
Colours are the same as used in that file + dark purple for UKUP.
See Image:Northern Ireland election seats 1997-2005-by.svg for corrisponding image with 2000 South Antrim by-election.
The strokes around the legend boxes aren't being drawn because of wikipedia's buggy SVG renderer.

PNG version can be found at File:Northern Ireland election seats 1997-2005.png
No machine-readable source provided. Own work assumed (based on copyright claims).
No machine-readable author provided. Nickshanks assumed (based on copyright claims).