Task: Question Answering
Input (English): Passage: Concurrently with designing churches and building railways, Sharpe was heavily involved in the civic life of Lancaster, particularly in pioneering sanitary reform.  By political persuasion he was a Conservative, and in 1837 he joined the local Heart of Oak Club, the core of the Lancaster Conservative Association. He was elected a town councillor for Castle Ward in 1841, a post he held for ten years, and in 1843 was appointed the town council's representative on the local Police Commission.  He was also a visitor to the national schools, and in November 1848 he was elected as mayor for year, at that time a position more like that of a "chief magistrate". Through these offices he became aware of the unsatisfactory state of sanitation in the town, and resolved to improve it. The town was overcrowded, it suffered from poor housing, open sewers, overflowing cesspits, and a very poor water supply, mainly from wells polluted by infiltration.  Many people suffered from typhus, and in 1848 there was an outbreak of cholera. The Police Commission had been established in Lancaster in 1825 with a wider role than suggested by its title, including "cleansing, lighting and watching" the town. However, there was constant friction between the Police Commission and the Town Council, the former tending to block any necessary reforms on the grounds of cost to the ratepayers.  The conflict was unresolved until the two bodies merged in 1849. The functions of the new body included the establishment of the first Lancaster Board of Health. 
Question: Which group tended to block any necessary reforms on the grounds of cost to the ratepayers?
Output (English): the Police Commission.