Kerr was a member of the Progressive Conservative Party and was the first person to hold the portfolio of environment minister in any provincial or federal cabinet in Canada.
[4] In that role, Kerr oversaw the Ontario government's response to the discharge of about 10,000 kilograms (22,000 lb) of mercury from the Dryden Chemical Company's chloralkali plant, into the headwaters of the 235 km (146 mi)-long Wabigoon River on Lake Wabigoon in the Kenora District of Northwestern Ontario from 1962 until 1970,[5] which caused mercury contamination in the region's lakes and rivers.
According to a 2018 article in The Guardian, in August 1970 Kerr had reassured the local community that the Wabigoon river would recover naturally within twelve weeks without government intervention or a clean up.
[10] He temporarily resigned from cabinet on February 21, 1975, after allegations that he had solicited and received money from a man involved in a harbour scandal in Hamilton.
A subsequent investigation found no grounds to warrant charges against Kerr, and he was briefly returned to cabinet before leaving again on July 18.
[13] He resigned a second time as Solicitor-General after he made a telephone call to an assistant crown attorney on behalf of a constituent who was facing trial for driving while his licence was suspended.