The judge could opt to delay the buyout further or block it on a more permanent basis when he next considers the legal challenge by the unions at a hearing on Monday.

The administration set a deadline for Thursday at 11:59 p.m. Eastern for employees to decide on the offer. But a federal judge in Massachusetts paused the deadline until at least a hearing set for Monday at 2 p.

The deadline for federal workers to receive financial incentives to quit is approaching. More than 2 million employees have until Thursday at 11:59 p.m.