Complex sentence: In 1993--94 Leek finished second in the Northern Premier League Premier Division, which should have been sufficient for promotion to the Football Conference, however they were refused promotion due to financial irregularities.
Split into simpler sentences: In 1993--94 Leek finished second in the Northern Premier League Premier Division, which should have been sufficient for promotion to the Football Conference. However, they were refused promotion due to financial irregularities.