The 23-year-old model and the Luton-based doorman both risk eviction on Friday (June 15) after receiving the most nominations when all housemates voted for the first time earlier today (June 11).
The nominations result was confirmed on Big Brother's official Twitter feed when links to their pictures were included in a message that read: "SPOILER ALERT! The nominations are in - click on the pics to find out who's up."
Arron received a total of five nominations, while Chris picked up four. Full details of how the group voted have yet to be announced by Channel 5.
Wildcard entrant Becky Hannon yesterday (June 10) won immunity from this week's eviction after passing her secret task to be chosen as one housemate's favourite person.
Becky was picked by Deana Uppal, who was granted safety from the first eviction in return for nominating three housemates to face the public vote on launch night last Tuesday (June 5).
Former glamour model Victoria Eisermann became the first person eliminated from this year's series on Friday (June 8), leaving over Deana's other choices Conor McIntyre and Lydia Louisa.