Qatar has expressed "deep concern" over Mohamed Morsi - Egypt’s first democratically elected president - being placed on death row, and has requested his release.
"Doha adds its voice to the countries calling for the verdict to be quashed and Morsi released," said a statement from the state-run Qatar News Agency.
The United States has criticised the sentencing of the deposed former president to death as being politically motivated.
Cairo’s Criminal Court sentenced deposed president Mohamed Morsi to death for breaking out of jail in 2011, despite deciding to revise a previous death sentence for espionage to 25 years in prison.
The Muslim Brotherhood's grand leader Mohamed Badie was also sentenced to death for breaking out of jail after he too had his previous death sentence for espionage lifted.
Seventeen other Muslim Brotherhood supporters were sentenced to death in the espionage case, including Khairat al-Shater and Mohamed al-Beltagy. Thirteen more defendants were additionally sentenced to death in absentia.
The defendants were accused of sending Muslim Brotherhood members to Gaza through tunnels to receive military training from the Iran’s Revolutionary Guard and the Lebanese Shiite group Hezbollah, after which they would return home and execute “acts of terrorism and disruption of the lives of peaceful citizens.”
All the verdicts are vulnerable to court appeals, which could lead to reduced sentencing.
Several Muslim Brotherhood leaders and Hamas leaders currently reside in Qatar, along with renowned Muslim cleric, 88-year-old Yusuf Qaradawi, who was also sentenced to death.
"The death sentences against political dissidents in Egypt harm security and stability, and close the door to reconciliation and harmony," according to the Qatari statement.
Doha, along with Ankara, has been outspoken about its wish for Morsi to be released. This has led to ties with Cairo has being greatly strained.
Qatar is the only Gulf country that did not back Egypt’s now-president Abdel Fattah el-Sisi, who was given immediate backing by Gulf neighbours Bahrain, Saudi Arabia and the United Arab Emirates. The dispute ended in a compromise in December, when Qatar pledged its support for Sisi, even though many leaders of Morsi's Muslim Brotherhood still reside in Doha.
The Egyptian government blacklisted the Muslim Brotherhood as a terrorist group. However, it recently removed the Palestinian resistance group Hamas from its terror list.
Morsi was elected as Egypt’s president in June 2012, making him Egypt’s first democratically elected president.
Within a year, however, pressure was placed on him to leave office amid street protests against his rule demanding early elections, as Egypt struggled with economic problems. A brutal military crackdown forced Morsi out of office which was followed by the bloody dispersal of the pro-Muslim Brotherhood camps at Rabaa and Nahda squares in Cairo.
More than 1,000 people were killed in the dispersal of the camps, and since July 2013 hundreds of Muslim Brotherhood members and sympathisers have been arrested and given severely harsh sentences.