Morgan Tsvangirai joined Robert Mugabe's government a year ago
Zimbabwe's Prime Minister Morgan Tsvangirai has joined President Robert Mugabe in dismissing calls to enshrine gay rights in the new constitution.
"I totally agree with the president," he said, state media report.
Homosexual acts are currently illegal in Zimbabwe. Mr Mugabe once said gays were "worse than pigs and dogs", sparking international condemnation.
Gay rights have become a controversial issue in several African countries in recent months.
Mr Tsvangirai joined his long-time rival Mr Mugabe in a power-sharing government a year ago but relations between the two men remain tense.
President Mugabe told a belated celebration of International Women's Day that he had recently learned of moves to introduce gay rights in the new constitution currently being discussed.
"That issue is not debatable, it's not up for discussion," he said, according to the state-owned Herald newspaper.
"It is just madness, insanity. The ancestors will turn in their graves should we allow this to happen."
And Mr Tsvangirai said he agreed.
"Women make up 52% of the population... There are more women than men, so why should men be proposing to men?"
Chesterfield Samba, director of the Gays And Lesbians of Zimbabwe (Galz), told the BBC News website he was seeking clarification of the comments.
But he said, if confirmed, they would be "very worrying".
He also confirmed that Galz would be making a submission to the constitutional review commission.
Although homosexual acts are illegal in Zimbabwe, Galz has an office in Harare and Mr Samba said the police generally left them alone.
Supporters of Mr Tsvangirai hope the new constitution will pave the way for free elections, possibly as soon as 2011.
In Uganda, an MP has introduced a draft bill which makes homosexual acts punishable by life in prison and death in some circumstances.
In Malawi, a gay couple has spent three months in jail after holding a party to celebrate their engagement.
And in Kenya, police intervened after rumours that a couple were planning a gay wedding.