at full stretch

be/work (at) full stretch - (работать)на пределе возможностей, с полной нагрузкой,полным ходом; [изо всех сил ]; полностью

Meaning: use as much energy as possible, or the greatest possible amount of supplies; work as hard as possible:
Fire crews are working at full stretch to cope with the accident.
When the plant is operating at full stretch it can employ 900 people.(CIDI)
See also [изо всех сил ], [with a vengeance]