Uganda on Tuesday condemned the Western response to the new law and said sanctions threats from donors amounted to "blackmail."
The law has been termed draconian on an already marginalized group, but hailed by some conservatives.
It seeks the death penalty for a "person convicted of aggravated homosexuality," and a 20-year prison sentence for a "person who commits the offense of homosexuality."
A 10-year prison sentence will be slapped on a "person who has been convicted of attempted homosexuality," while a "child found guilty of homosexuality" will be handed down a three-year sentence.
Richard Lusimbo, director general of the Kampala-based UKPC, told VOA that its legal redress is based on what the country's 1995 constitution stipulates "on the rights of all Ugandans," describing the legal challenge as "a matter of national interest."
The consortium comprises activists who describe themselves in the petition made available to VOA as "committed proponents of the rule of law, fundamental human rights and freedoms, and the promotion of progressive constitutionalism."
"The Constitution of Uganda is very clear on the rights of all Ugandans and it’s on this basis that we (went) to the Constitutional Court to seek legal redress," Lusimbo said.
"Because when you look at the right to health, the right to belong, and if you look at even employment, because - again within this law - if you identified as an LGBTQ person that could have lots of negative implications in terms of even how you can access work."
President Joe Biden called Uganda's Anti-Homosexuality Act "a tragic violation of universal human rights."
"I join with people around the world—including many in Uganda—in calling for its immediate repeal. No one should have to live in constant fear for their life or being subjected to violence and discrimination. It is wrong," a statement from the White House said.
The assent of the bill into law by Museveni on May 26, has sent shivers down the spine of LGBTQ+ activists and allies across the continent.
In Ghana, where a group of legislatures have laid a similar legislation known formally as the "the Promotion of Proper Human Sexual Rights and Ghanaian Family Values Bill," sexual minorities are on the edge.
Angel Maxine, Ghana's first open transgender musician, told VOA that even though the bill is yet to pass, its adverse impact is being felt among sexual minorities in the West African nation.
Ghana's proposed bill will impose up to ten years prison sentence on anyone who identifies as LGBTQ+ or even an ally. Amnesty International defines an ally as one who takes action to support a group they are not part of.
"Living openly as a trans woman has closed a lot of doors for me. It has taken a lot of things away from me…it has taken people away from me," she said.
"I cannot live my life as a normal human being or a normal Ghanaian who can walk freely on the street or partake in every other activity that any other Ghanaian can partake in. I can’t go out to look for a job because nobody wants to employ me."
Co-sponsor of the bill and member of parliament Sam George told VOA that he's determined to "see the bill through."
"The bill that we’re sponsoring is one that is responding to the growing threat to Ghana’s culture and traditions by pro-Western forces and influences seeking to introduce things that are not acceptable by our culture," he said.
Both Uganda and Ghana have closed LGBTQ+ organizations, known as safe spaces, that support the mental health of community members. There are contentions in Kenya and Tanzania over LGBTQ+ rights.
As such anti-gay sentiments rise, activists continue working to affirm the human rights of LGBTQ+ persons in Africa.
"We are part of the U.N. LGTBQ core group where we have access to politicians and diplomats who can help us open paths for dialogue with lawmakers in countries where we are concerned about the LGBTQ community members' safety," said Matuba Mahlatjie, an official at Outright International in Pretoria.
But not all is gloomy for the LGBTQ+ community and its allies. There have been efforts by some African states to roll back harsh laws against homosexuality - notably, Angola, Botswana, and Gabon.
In Africa, 32 states still criminalize same-sex relationships — that’s half of the 64 countries with anti-gay laws around the world.
Some such as Nigeria and Egypt already have harsh laws making LGBTQ+ persons a target in their communities.