KHARTOUM - Sudan's opposition parties have pledged to step up anti-regime protests and press for a multi-party system, their alliance said on Thursday.
About 17 political parties signed the charter on Wednesday, along with non-governmental organisations and individuals, said Farouk Abu Issa, head of the opposition coalition.
The aim is "to dismantle the one-party regime and bring about a multi-party system," he said.
Change will come "by mobilising our people" with larger peaceful protests against the ruling National Congress Party, including on Friday which has become a focus of anti-government demonstrations, he said.
"This is the way we have chosen," he said.
Protests against high food prices began on June 16 at the University of Khartoum.
After President Omar al-Bashir announced austerity measures, including tax hikes and an end to cheap fuel, the protests spread to include a cross-section of people around the capital and in other parts of Sudan.
Demonstrators have burned tyres, thrown stones and blocked roads in a call for regime change that has been met by what the European Union called "a violent crackdown."
Last Friday, hundreds of protesters who gathered beside the Umma party mosque in Khartoum's twin city of Omdurman were confronted with tear gas and rubber bullets, witnesses said.
The Umma party, led by former Prime Minister Sadiq al-Mahdi, is a key member of the opposition alliance, along with Islamist opposition leader Hassan al-Turabi.
A diplomatic source last week said that opposition parties had been relatively quiet during the protests, and activists have dismissed the political opposition as weak.
Issa noted that popular mobilisation has twice toppled regimes in Sudanese history.
In 1964, the death of student activist Ahmed al-Qureshi sparked the "October Revolution" which brought down the military government then in power after tens of thousands protested.
During an economic crisis in 1985, huge crowds marched in an uprising which led to the bloodless overthrow of president Gaafar al-Nimeiry. Bashir seized power from Mahdi, who was democratically elected, on June 30, 1989.
The president has played down the current demonstrations as small-scale and not comparable to the Arab Spring uprisings in Egypt and elsewhere, maintaining that he himself remains popular.