Uganda on Tuesday passed a controversial bill to limit public demonstrations, criticised by rights groups as a "devastating blow" to free speech and political debate.

The Public Management Order bill places tough restrictions on public meetings, including granting police the power to block a gathering of as few as three people to debate politics.

It requires a written notice of planned meetings to be submitted to police a week in advance, and allows police to block or prevent a public meeting if they deem it a breach of the peace.

Moses Ali, deputy leader of government business in parliament and a member of the ruling National Resistance Movement (NRM) party, said the bill would "protect people's interests".

"We have as much as possible tried to accommodate the views expressed by the opposition as well as what the public thinks," he said.

But opposition member of parliament, Moses Kasibante, an independent lawmaker, said the bill would be challenged in the constitutional court.

"It is a bad law which restricts freedom of speech and expression and hinders democratic values," he said.

"We have resolved to challenge it in the courts of law because it is against the constitution of Uganda."

Amnesty International criticised the bill as imposing "wide ranging restrictions on public meetings."

"The Ugandan government must stop trying to crush the rights to free speech and peaceful demonstration as enshrined in its own constitution as well as international law," said Amnesty's deputy Africa director Sarah Jackson.

"This insidious bill is designed to intimidate civil society and shrink Uganda's diminishing political space further still,"

Human Rights Watch called the bill a "devastating blow for freedom of expression and assembly" in the country.

Ugandan police regularly try to block demonstrations by the opposition supporters, who have staged a series of protests in recent years over rises in the cost of living.

Key opposition leader Kizza Besigye has been repeatedly arrested or blocked from leaving his home, even though he is no longer formally head of the Forum for Democratic Change (FDC) party.

In May, police shut the two main independent newspapers and two radio stations for 10 days after they reported arguments among army generals over whether the son of President Yoweri Museveni was to succeed him.

"Political demonstrations already face serious obstacles, including the use of live ammunition on innocent bystanders and demonstrators," HRW's Maria Burnett added.

"With this law in force, any spontaneous peaceful demonstration of more than three people will be a criminal act. The 2016 elections are just around the corner and space for political dissent is shrinking fast."