It is feared a new shopping centre could attract staff away from the care sector in Oxfordshire.
Recruitment to fill 3,000 new jobs at Westgate Oxford has started at a time when 1,855 people are on Job Seeker's Allowance in the county.
Westgate Oxford said it had plans for recruitment and was confident it could fill the positions.
But Penny Thewlis from Age UK said it could attract people who "might otherwise be attracted by caring".
She added that areas of Oxfordshire were already experiencing carer shortages.
"The balance is very fine, it won't take many people making decisions to leave social care work to tip that balance," she said.
Retail consultant Keith Slater said recruiting workers for Westgate would not be easy.
"It is not going to be very long before Bicester Village has a big extension, another 30% space there, so there is going to be another big chunk of jobs.
"So it could be very, very, difficult getting the right calibre of staff to come into these jobs."
The £440m Westgate Oxford shopping centre is due to open in October.
General manager Brendan Hattam said: "We've been working hard for a couple of years on our plans for recruitment."
He added: "We actually think it would be very attractive for people to work here."