Channel 5 confirmed earlier this evening that the two housemates are up for the public vote ahead of Friday's elimination show.
The housemates took part in face-to-face nominations earlier today around a cowboy campfire as part of their Gold Rush challenge.
Luke Scrase, Sara McLean, Scott Mason had previously won immunity from nomination this week after succeeding in the Rocky River of Gold task.
It is the second time Lauren has faced eviction, while Luke A is a first-time nominee.
Voting for this week's eviction is now open online via the Channel 5 website.
Photo gallery - Big Brother Day 41:
Copyright: Channel 5