Phinéra-Horth joined the Guianese Socialist Party (PSG) in 1988, of which she was treasurer for two years.

[1] Supported by both the PSG and Walwari, in 2014 Phinéra-Horth left Alexandre's “Guiana 73” movement.

On 20 May 2016, she founded a new political party - Guyana's New Force (fr), which is primarily active in Cayenne.

[4][5] In May 2021, as part of an appearance on the television programme Politik Hebdo, Phinéra-Horth revealed that she was opposed to COVID-19 vaccinations.

[6] In February 2022, she was taken to court, accused of falsely collecting a salary as a speech therapist during her time as mayor from 2013 to 2016.