He represents the district of Sydney-Whitney Pier and is the interim leader of the Nova Scotia Liberal Party.

[3] Mombourquette attended Cape Breton University, serving as both President and Vice-President of the student union.

[4] In 2013, Mombourquette ran for the Liberals in Sydney-Whitney Pier in the 2013 election, losing to incumbent MLA Gordie Gosse.

[4][5] He was elected to the Nova Scotia House of Assembly in a by-election on July 14, 2015, for the riding of Sydney-Whitney Pier.

[11][12] As of September 22, 2024, Mombourquette serves as the Official Opposition critic for Education and Early Childhood Development as well as for Community Services.