Merceron was educated at Merchant Taylors' School in the City of London, following which he spent time working in his father's pawnshop and in a local lottery office.
In 1798 Merceron became embroiled in a scandal over the conditions at Coldbath Fields Prison in Clerkenwell, where several radical sympathisers, including Colonel Edward Despard, were being held without trial.
[5] The scandal was exposed in Parliament by the young radical MP Sir Francis Burdett, who used it as the basis of his campaign against the Mainwaring family in the 1802 and 1804 Middlesex parliamentary elections.
Merceron's wealth and influence continued to grow, as he became a director of a number of important businesses including the East London Water Works Company and the Hand-in-Hand Fire Office.
[2] After several years of often violent disorder in Bethnal Green, a turning-point came when King was supported by a local businessman and philanthropist John Barber Beaumont and by Merceron's long-serving vestry clerk, who gave evidence against Merceron before a House of Commons select committee led by Whig MP Henry Grey Bennet in 1816,[7] and then instigated a prosecution for the appropriation of £925 of parish funds and partiality in the renewal of public house licences.
[2] However, the succeeding parochial regime in Bethnal Green was insufficiently strong to retain power against the Merceron faction and within a month of his release from prison he had regained control of the vestry.
The description of Merceron as a political ‘Boss' reflected comparisons drawn by the Webbs with William Tweed, the corrupt New York municipal politician and leader of Tammany Hall in the 1860s.
[2][3] In 2019, a partly fictitious version of Merceron, played by Tim Dutton and drawing on a number of incidents described in Woodford's biography, was written into Series 5 of Poldark by Debbie Horsfield.