Complex sentence: Sharp criticism was levelled in Parliament and in the press against the extreme slowness with which taxes long overdue were being collected, a regrettable state of affairs which was partly attributable to the overworked condition of revenue and taxation officials.
Split into simpler sentences: Sharp criticism was levelled in Parliament and in the press against the extreme slowness with which long overdue taxes were being collected. The slowness in tax collection was partly attributable to the overworked condition of revenue and taxation officials.