On Monday, June 28, over a dozen human rights organizations will join in a campaign to demand a halt to executions in Egypt. Led by Reprieve, a UK-based rights advocacy group, the organizations will publish a joint letter and call for a Tweetstorm using the hashtag #StopEgyExecutions.

The launch of the campaign coincides with the end of a two week period in which the men could be granted amnesty. On June 14, Egypt’s high court upheld death sentences for the 12 men, including senior leaders in the country’s political opposition. The ruling, which cannot be appealed, places the men on death row and their execution may be imminent. Egypt is one of the world’s worst executioners, carrying out dozens of executions each year, despite systematic violations in its courts.

“The execution of these twelve men must not go forward.” said Jeed Basyouni, who leads Reprieve’s work on the death penalty in the Middle East and North Africa. “With flaws at all stages of this unlawful mass trial, the men were never given the opportunity of a fair hearing. Until Egypt addresses systematic violations occurring in its justice system, any executions carried out are absolutely unconscionable.”