The charges, in relation to riots in the Egyptian city of Minya during which a policeman was killed, have cast doubts over Egypt's "transition towards democracy".
Responding to the verdict Ashton said, "The EU is against the death penalty in all cases and therefore strongly opposes the recommendation of the death penalty for an additional 683 persons by a court in Minya in Egypt which has already issued a similar recommendation for 529 persons in late March.
"It is also of particular concern that of this latter group, the recommendation has been confirmed in the case of 37 persons."
The British official continued, "These mass trials are clearly in breach of international human rights law: the exact charges against each defendant remain unclear, the proceedings lack the most basic standards of due process and the verdicts appear grossly disproportionate, failing short of complying with the principle of individual sentencing."
According to reports the verdicts were delivered by judge Said Yussef following a five minute trial.
She went on, "The EU reiterates its call on the Egyptian judicial authorities to ensure, in line with international standards, the defendants' rights to a fair and timely trial based on clear charges and proper and independent investigations, as well as the right of access and contact to lawyers and family members.
"The EU observes a very worrying trend regarding the compliance of Egypt with its international human rights obligations," she said, adding, "As well as the seriousness of Egypt's transition towards democracy which requires a legal and judicial framework respecting international human rights standards.
She concluded, "The EU calls on the Egyptian authorities to immediately reverse this trend which jeopardises any prospects for overcoming divisions within society and to ensure progress towards a truly democratic, stable and prosperous Egypt, through a political process open to all citizens."
Meanwhile ALDE deputy Marietje Schaake, who has actively advocated for the democratic rights of Egyptians, said, "This is an unacceptable verdict and a very concerning part of a broader campaign by the Egyptian regime to silence every form of dissent and criticism.
She expressed concern that, "Press freedom and freedom of expression are coming under increased pressure in the run-up to the upcoming presidential elections.
"That is a dangerous development for the future of Egypt and a threat to the rights and freedoms of the Egyptian people," warned the Dutch MEP.
"The European Union needs to condemn the recent developments in Egypt, and especially the wanton use of the death penalty and mass processes to silence and intimidate opposition.
Referring to the role of the Europe, she said, "EU foreign policy chief Ashton needs to take a clear position and put forward a European strategy with regard to Egypt.
"Egypt has the potential to be an important partner in the region and we must show that we continue to support the Egyptian population," adding, "Europe has been too quiet and too absent."
Further condemnation came from Amnesty International's Hassiba Hadj Sahraoui, who said, "These decisions once again expose how arbitrary and selective Egypt's criminal justice system has become.
"The court has displayed a complete contempt for the most basic principles of a fair trial and has utterly destroyed its credibility. It is time for Egypt's authorities to come clean and acknowledge that the current system is neither fair nor independent or impartial," he said.