He served as reeve of the then-Township of York from 1957 to 1960, when he was unseated by a court order due to a conflict of interest scandal involving his house which was built on land purchased from the township.
[5] Tonks was accused of having, while serving as reeve, rigged the sale of a tract of municipal land to himself in 1957, at a favourable price, on which he built his family's home.
Revelations made during the royal commission inquiry led a group of ratepayers to seek a court order unseating Tonks as reeve in 1960.
They succeeded, but the order was overturned by the court of appeal and Tonks was reinstated as reeve, only to be defeated when he ran for re-election in the December 1960 municipal election by reformer Frederick Charles Taylor by an almost 3 to 1 margin.
[13][14] He lost an attempt to be elected to York's Board of Control in 1969, and then returned to council again as an alderman for Ward 5 in 1972, where he remained until his retirement in 1988.