Malawi has suspended anti-gay laws and ordered police not to arrest people who commit homosexual acts pending a debate on whether to repeal the legislation.

President Joyce Banda's government announced on Monday that it had imposed a moratorium on the laws until the 193-member parliament could decide on the highly contentious issue.

The move was welcomed by Amnesty International as "a historic step forward", but local activists urged caution.

Sections 153 and 156 of Malawi's penal code criminalise sexual conduct between men and anyone convicted faces up to 14 years' imprisonment, with or without corporal punishment. Section 137A of the penal code criminalises "indecent practices between females", with anyone found guilty liable to five years in prison.

Ralph Kasambara, the justice minister, said: "There is a moratorium on all such laws, meaning that police will not arrest or prosecute anyone based on these laws."

The laws that criminalise homosexuality in the deeply conservative country will not be "enforced until the time that parliament makes a decision", added Kasambara, who is also attorney general.

If the laws are found to be unconstitutional, he said, it would be an embarrassment to the government, but if they are found to be valid, police will be able to act. "It is better to let one criminal get away with it rather than throw a lot of innocent people in jail," said Kasambara.

In 2009, two men were arrested and charged with public indecency after becoming the first gay couple to marry in the former British protectorate. The prosecution drew condemnation from around the world including from Amnesty. Noel Kututwa, its southern Africa director, said: "Amnesty International welcomes Minister Kasambara's statement and hopes it serves as the first step towards ending discrimination and persecution based on real or perceived sexual orientation and gender identity in Malawi.

"We urge the government not to lose momentum on this basic human rights issue and to ensure the full repeal of these discriminatory and hate-filled laws."

Gay rights campaigners in Malawi called for the government to go further. Gift Trapence, director of the Centre for the Development of People (CEDEP), which now openly operates in the country, said: "This is a good stepping stone but we want a total repeal of the sodomy laws for Malawi to align itself with international human rights standards.

"Suspending is something else and repealing is another thing. We want the government to repeal these archaic laws."

Trapence said CEDEP regarded the sodomy laws as "still intact until they are repealed" and said Malawians, who generally favour prohibition, should debate the issue with "sober minds and remove all prejudices".

Chrispin Sibande, a rights lawyer, said the moratorium was "very shaky" because it was not supported by a clear legal order. He called the government move "political goodwill" that could change at any time.

Michael Kaiyatsa, a programme officer with another leading rights group, the Centre for Human Rights and Rehabilitation, said the suspension was "a welcome development and a step in the right direction". But he said rights groups wanted a "permanent solution – the complete repeal of sodomy laws".

Banda, who came to office in April following the death of President Bingu wa Mutharika, initially said her government would decriminalise homosexuality but later made a U-turn and said parliament was better placed to solve the controversial issue.

A recent report presented to Banda recommended decriminalisation of same-sex marriages as a way of fighting the spread of HIV and Aids.