The Muslim Brotherhood and Amnesty International have slammed a lengthy jail term handed down to the ousted Egyptian president, Mohamed Morsi, over the arrest and torture of protesters in 2012.

The Brotherhood condemned the verdict in a statement on Tuesday, warning that it would ignite a new revolutionary move.

The movement said “this illegitimate verdict that was forced through by the illegitimate authorities in Egypt will not be overlooked by the revolutionaries… Today’s illegitimate verdict will fuel the revolutionaries further to resist military rule in Egypt as they have been resisting over the past 22 months.”

Amr Darrag, a former minister under Morsi and a senior Muslim Brotherhood figure, also criticized the verdict, saying that if the international community does not condemn this “farce”, harsher penalties will follow.

“If, as they expect, the international community would just issue some statements and just watch, I believe they would be encouraged for the coming other cases to give harsher sentences, which I believe would be death sentence,” Darrag stated.

He also said that Tuesday's verdict was “scripted and controlled by the government.”

Hassiba Hadj Sahraoui, deputy Middle East and North Africa director at Amnesty International, also condemned the prison sentence on Tuesday, saying the “verdict shatters any remaining illusion of independence and impartiality in Egypt's criminal justice system.”

“Any semblance of a fair trial was jeopardized from the outset by a string of irregularities in the judicial process and his arbitrary, incommunicado detention.”

Earlier in the day, an Egyptian court sentenced Morsi to 20 years in prison over ordering the arrest and torture of demonstrators outside his presidential palace in December 2012, when clashes erupted after he issued a controversial constitutional declaration in November of the same year to expand his powers.

The verdict, the first ruling against the North African country’s first elected president, was issued by the Cairo Criminal Court on Tuesday as Morsi and other defendants, mostly leaders from the banned Muslim Brotherhood movement, stood trial in a courtroom at Egypt's national police academy.

The court, however, acquitted the defendants of charges of inciting murder in the deaths of a journalist and two protesters during the December clashes in Cairo.

Twelve Muslim Brotherhood leaders and supporters, including Mohamed el-Beltagy and Essam el-Erian, also received the same sentence as Morsi.

Hundreds of Muslim Brotherhood members and supporters have faced mass trials following the military ouster of Morsi in 2013.

In July 2013, Morsi, the country’s first democratically-elected president, was ousted in a military coup led by the former head of the armed forces and the current President Abdel Fattah el-Sisi.

The Egyptian government has been cracking down on any opposition since Morsi was ousted.