Over the weekend, Tim Cook reaffirmed his support for Deferred Action for Childhood Arrivals (DACA), the Obama era policy that allows some illegal immigrants to defer deportation. After Attorney General Jeff Sessions took to a podium at the Department of Justice earlier today to confirm the administration’s decision, Cook emailed Apple staff a long memo urging Congress to make the policy permanent.

The memo, which was obtained by TechCrunch this morning, notes Cook’s “deep dismay” at the planned end for a program that could impact the lives of 800,000 Americas. As the executive noted over the weekend, that list includes more than 250 Apple employees.

Cook relays the stories of some of the employees who contacted him following his tweet over the weekend and the release of a letter last week that he cosigned along with other top executives from companies like Amazon, Facebook and Microsoft.

“On behalf of the hundreds of employees at Apple whose futures are at stake,” Cook writes, “on behalf of their colleagues and on behalf of the millions more across America who believe, as we do, in the power of dreams, we issue an urgent plea for our leaders in Washington to protect the Dreamers so their futures can never be put at risk in this way again.”

The planned end of DACA is just the latest in a number of policy decisions that have drawn a wedge between Trump and the industry leaders who sat down with him at a tech summit just ahead of his inauguration. The full text of the letter can be read below.