An Egyptian court has overturned a death sentence on the former president Mohamed Morsi and ordered a retrial.
The democratically-elected president was deposed in a 2013 coup led by ex-army chief Abdel Fatah al-Sisi after mass protests against Morsi's rule.
Morsi was immediately arrested following the coup and has been convicted in a number of high-profile cases under the new regime. He had been convicted to death in connection with a mass jail break in 2011.
Tuesday's Court of Cassation ruling means he no longer faces execution, but he is still serving lengthy jail sentences over other charges.
International confidence in Egypt's political future has been undermined by a court's decision to confirm death sentences for the Muslim Brotherhood's leader and 182 others, William Hague has said.
The Foreign Secretary urged the authorities to review the sentences which he claimed had damaged the reputation of Egypt's judicial system.
"The United Kingdom opposes the death penalty in all circumstances as a matter of principle." Mr Hague said.
An Egyptian court confirmed on Saturday death sentences against the leader of the outlawed Muslim Brotherhood and 196 of his supporters, Al Arabiya TV said quoting a lawyer involved in the case.
An Al Jazeera journalist who spent more than 130 days on hunger strike in protest at his detention has been freed from an Egyptian prison.
Abdullah Al-Shamy, 26, was released today on medical grounds after spending nearly a year in detention without charge.
Three other journalists including the Australian national Peter Greste are still being held by Egyptian authorities in a case that has caused worldwide outcry.
They are accused of aiding the former president Mohamed Mursi's Muslim Brotherhood, which was banned as a terrorist group by the army regime which ousted the Mursi last July.
Muslim Brotherhood called the sentencing to death of 529 of its supporters by an Egyptian court "inhumane and a clear violation of all norms of humane and legal justice."
A statement from the religious and political party's London office described the sentencing as "shocking and unprecedented".
"The verdict is yet another clear indication that the corrupt judiciary is being utilized by the coup commanders to suppress the Egyptian revolution and install a brutal regime which surpassed decades long of oppression and tyranny in Egypt's history," Muslim Brotherhood said.
The group stressed it will appeal the court ruling "and defend basic rights of Egyptians".
Three journalists working for the Gulf new agency Al Jazeera have been detained in Egypt accused of broadcasting illegally from a hotel suite among other allegations.
Al Jazeera has named them as former BBC journalist Peter Greste, Baher Mohamed and Mohamed Fahmy.
A fourth person - a cameraman - was arrested with them on Sunday but has since been released. The other three have been remanded in custody for 15 days.
Egyptian authorities have accused Al Jazeera of backing the Muslim Brotherhood, which was recently ruled a terrorist organisation.
The Brotherhood leader and presidential candidate Mohamed Morsi was overthrown last year.
University buildings have been torched and one student killed as supporters of the Islamist Muslim Brotherhood clashed with police at the Cairo campus of Al-Azhar University, state media reported.
State-run newspaper Al-Ahram said that security forces fired teargas to disperse pro-Brotherhood students who were preventing their classmates from entering university buildings to take exams.
Protesters threw rocks at police and set tyres on fire to counter the teargas. Al-Ahram quoted a health ministry official as saying that one student had been killed and five injured.
The violence followed clashes across the country on Friday in which at least five people died.
Two college buildings caught fire in Saturday's violence. State TV broadcast footage of black smoke billowing from the faculty of commerce building and said "terrorist students" had set the agriculture faculty building on fire as well.
An Islamist student was killed and several arrested after supporters of the now outlawed Muslim Brotherhood clashed with Egyptian police at a university in Cairo, according to state media reports.
Egyptian students loyal to the Muslim Brotherhood set fire to two building amid clashes with police at the Cairo campus of Al-Azhar University, state television reported.
A student activist said a supporter of the Brotherhood had been killed - a claim denied by a security source.
State-run newspaper Al-Ahram said the clashes began when security forces fired teargas to disperse pro-Brotherhood students who were preventing their classmates from entering university buildings to take exams. Protesters threw rocks at police and set tyres on fire to counter the teargas.
Egyptian authorities have detained senior Muslim Brotherhood leader Essam el-Erian, the latest arrest in a government crackdown against the Islamist movement, Reuters reported, citing an Interior Ministry source.
Erian, the deputy leader of the Brotherhood's Freedom and Justice party, was taken into custody from a residence in Cairo where he had been in hiding.
"Yes, he's been arrested and details will soon be released," the source told Reuters.