Mass trials in Egypt resulting in hundreds of death sentences breach international norms and drive concerns over Cairo's commitment to human rights, EU foreign affairs chief Catherine Ashton says.
"These mass trials are clearly in breach of international human rights law," Ashton said in a statement on Tuesday.
"The exact charges against each defendant remain unclear, the proceedings lack the most basic standards of due process and the verdicts appear grossly disproportionate."
On Monday, a court imposed death sentences on 683 suspected Islamists - including Muslim Brotherhood leader Mohamed Badie. The sentence came after a brief hearing, and as the authorities continue a crackdown on supporters of ousted Islamist president Mohamed Morsi.
Another 529 people were also sentenced to death in March, although some sentences have since been commuted.
Ashton called on the Egyptian authorities to ensure that the judicial process met international norms, notably the right to a fair and timely trial based on clear charges, along with right of access and contact to lawyers and family.
Recent events, she said, pointed to "a very worrying trend regarding the compliance of Egypt with its international human rights obligations".
She said there is concern in Brussels over "the seriousness of Egypt's transition towards democracy which requires a legal and judicial framework respecting international human rights standards".
"The EU calls on the Egyptian authorities to immediately reverse this trend," she said.
The United States has urged Egypt to reverse the court decisions while UN Secretary General Ban Ki-moon said he was "alarmed" by the sentencing.
The Minya court in southern Egypt, presided over by judge Said Youssef Sabry, is set to confirm the death sentences on June 21.
It reversed 492 of 529 death sentences it passed in March, commuting most of them to life imprisonment.
