Patrick Harvie has accused First Minister John Swinney of taking the country back to the “repressive values of the 1950s” by making Kate Forbes his deputy.
The Scottish Greens co-leader, who is bisexual, suggested the FM’s second in charge had made LGBT people in Scotland worry that their human rights are at risk.
Forbes has previously said she would have voted against same-sex marriage.
Harvie said the new deputy first minister has expressed judgmental attitudes on abortion as well as those who have sex out of wedlock.
The Green MSP was a Scottish minister, alongside his co-leader Lorna Slater, until two weeks ago when then-first minister Humza Yousaf sacked him while ending their power-sharing agreement.
Swinney succeeded him as SNP leader on Monday and as First Minister on Tuesday.