An Egyptian court upheld a death sentence against deposed president Mohamed Morsi for plotting jailbreaks and attacks on police during the 2011 uprising.
The court had initially sentenced Morsi and more than 100 other defendants to death last month.
Tuesday's ruling comes after the court consulted Egypt's grand mufti, the government interpreter of Islamic law who plays an advisory role.
Earlier on Tuesday, the same court sentenced Morsi, the country's first democratically elected president, to life in prison on charges of spying for the Palestinian Hamas movement, Lebanon's Shia Hezbollah, and Iran.
Tuesday's verdicts can be appealed.
Then army chief and now President Abdel Fattah el-Sisi ousted Morsi on July 3, 2013, and since then has overseen a sweeping crackdown against his supporters.
The crackdown has left hundreds of Muslim Brotherhood supporters dead and thousands jailed.
Hundreds have been sentenced to death after speedy mass trials described by the United Nations as "unprecedented in recent history".
In the jailbreak trial, exiled Egyptian-born cleric Yusuf al-Qaradawi was also condemned to death in absentia from his base in Qatar.
Muslim Brotherhood Freedom and Justice Party spokesman Nader Oman told Al Jazeera from his base in Istanbul that his organisation was surprised by Tuesday's verdict.
"I'm surprised because the charges are groundless and there is no chance for any of the defendants to defend themselves," Oman said.
"The Muslim Brotherhood is an organisation that has gone on for more than 80 years. Imprisoning our leaders will not stop us from fighting."
Source: Al Jazeera and agencies