Metropolitan Police Act 1839

From the longer Wikipedia page

The Metropolitan Police Act 1839 (2 & 3 Vict c 47) is an Act of the Parliament of the United Kingdom. The Act enlarged the district of, and gave greatly increased powers to the Metropolitan Police established by the Metropolitan Police Act 1829. It is one of the Metropolitan Police Acts 1829 to 1895.

Section 2 of the Act allowed for the enlargement of the Metropolitan Police District to include places in a radius of 15 miles (24 kilometres) from Charing Cross.

Section 5 gave constables of the Metropolitan Police all "powers and privileges of constabulary" in the counties of Berkshire and Buckinghamshire and on the River Thames within or adjoining Middlesex, Surrey, Berkshire, Essex, Kent and the City of London (the MPA 1829 had already given them constabulary powers within Middlesex, Surrey, Essex and Kent).