Sudanese political parties have rejected the government’s decision to normalise relations with Israel, with officials saying they will form an opposition front against the agreement.

Dozens of Sudanese people demonstrated in the capital Khartoum on Friday following the joint statement from Israel, Sudan and the United States on Friday saying that the two countries agreed to “end the state of belligerence between their nations”.

A statement from Sudan’s Popular Congress Party, the second most prominent component of the Forces of Freedom and Change (FFC) political coalition, said Sudanese people are not obligated to accept the normalisation deal.

“We see that our people, who are being systematically isolated and marginalised from secret deals, are not bound by the normalisation agreement,” the statement said.

“Our people will abide by their historical positions and work through a broad front to resist normalisation and maintain our support for the Palestinian people in order for them to obtain all their legitimate rights.”

Sudan’s former Prime Minister Sadiq al-Mahdi also slammed the announcement, adding that he withdrew from a government-organised religious conference on Saturday in Khartoum in protest.

Al-Mahdi, who is the country’s last democratically elected premier and heads the country’s largest political party, said: “This statement contradicts the Sudanese national law … and contributes to the elimination of the peace project in the Middle East and to preparing for the ignition of a new war.”

Kamal Omar, a leader in the Popular Congress Party, said in a separate statement that Sudan’s transitional government is not elected and therefore not authorised to normalise relations with Israel.

“This transitional government hijacked the Sudanese position to satisfy regional and international intelligence agencies,” he said.

Protesters in Khartoum took to the streets and chanted “no peace, no negotiation, no reconciliation with the occupying entity” and “we will not surrender, we will always stand with Palestine”.

Muhammad Wadaa, a leader in the Sudanese Baath Party, which is part of the FFC, said the anti-normalisation front includes a civil force and influential parties from within and outside the forces of freedom and change.

Wadaa said there are a number of parties within the FFC that warned the transitional government they will withdraw their support if normalisation with Israel was agreed to.

“Normalisation with Israel is a move that is rejected. The government is not authorised to take such a decision with a racist state that practises religious discrimination,” he said.

Wadaa told Al Jazeera that “the government made a big mistake and it is a step that will not achieve economic abundance”.

Palestinian officials reacted with dismay as Sudan became the third country to normalise relations recently, after the United Arab Emirates and Bahrain.

Palestinian Authority (PA) President Mahmoud Abbas denounced the deal and said the only path towards peace is by resorting to international law to make Israel end its occupation of Palestinian territories.

However, according to Al Jazeera’s Nida Ibrahim, many Palestinians believe the PA does not have much to offer other than condemnation.

“For many political analysts here, Palestinians have their backs against the wall and really don’t have much to hope for, other than Trump would not get a second term in office,” she said, speaking from the occupied West Bank city of Ramallah.

“Many Palestinians on social media say the Sudanese people’s hearts are with the Palestinian people but they were dragged into this by their military rulers.”

On Saturday, Iran’s foreign ministry slammed Sudan’s move, saying: “Pay enough ransom, close your eyes on the crimes against Palestinians, then you’ll be taken off the so-called ‘terrorism’ blacklist.”

“Obviously the list is as phoney as the US fight against terrorism. Shameful!” it added.