The UN's human rights office on Tuesday took Egypt to task over a planned law on public protests, saying it would curb freedoms and breach international rules.

"Although freedom of assembly can be subject to certain restrictions, freedom should be considered the rule, and restrictions the exception," Rupert Colville, spokesman for the UN High Commissioner for Human Rights, told reporters.

He said draft legislation approved last week by Egypt's cabinet would undermine "one of the cornerstones of democracy".

The draft stipulates that organisers must inform authorities in advance of plans to protest and the interior ministry has the right to reject a demonstration.

Protests will be restricted to a specific location in each province to be decided by the governor.

The draft also prohibits setting up platforms for speakers and the use of tents during sit-ins, as well as the carrying of banners or the chanting of slogans deemed defamatory or insulting to religion or state institutions.

The Egyptian government argues that the legislation -- which still needs to be ratified by the upper house of parliament -- is meant to prevent the mixing of peaceful and violent protests.

Colville said freedom of assembly was protected by a raft of international human rights accords ratified decades ago by Egypt.

"No one should be criminalised or subjected to any threats or acts of violence, harassment or persecution for addressing human rights issues through peaceful protests," he said.

Egypt has witnessed violence, insecurity and price hikes, fuelling political turmoil already plaguing the country.

Protests by Egyptians who accuse Islamist President Mohamed Morsi of betraying the revolution that brought him to power, have often turned into violent and sometimes deadly clashes with police.