Complex sentence: For most of its existence it made large losses and was subsidised by the taxpayer, particularly the railways division, and this caused the public and politicians to demand "make CIÉ pay".
Split into simpler sentences: For most of its existence CIÉ, in particular its railways division, made large losses and was subsidised by the taxpayer. This provoked demands from the public and politicians to "make CIÉ pay".