Episode 40 of The Trigan Empire
A National Emergency
aka The Outlaw Planet (the Collection)
De planeet der ballingen (Dutch title)
The Planet of the Exiles (Dutch title, translated)
A National Emergency was originally published in 5 installments in issues 606 (25 August 1973) to 610 (22 September 1973) of Look and Learn magazine.
It is reprinted in the Don Lawrence Collection Volume 10, The House of the Five Moons.