A vote to remain in the EU could spark a mini "hiring boom" among employers over the second half of the year, according to a new report.
On the other hand, a vote to leave is likely to see companies abandoning projects, shelving new expenditure and freezing hiring during a "prolonged period of uncertainty", said the Recruitment & Employment Confederation (REC).
A survey of 600 employers found that half anticipate skills shortages for permanent staff.
Firms flagged up a shortage of candidates to fill permanent and temporary jobs in areas including engineering, technology, health and social care and hospitality.
REC chief executive Kevin Green said: "The UK jobs market is at a tipping point, with the decision over our EU membership making a difficult situation worse. Whilst hiring has slowed down in recent months due in part to the Brexit question and global economic uncertainty, employers are telling us that finding candidates to fill vacancies is a difficult challenge.
"A vote to remain in the EU could release pent-up demand, with a mini hiring boom over the second half of the year.
"On the other hand, a vote to leave is likely to see employers abandoning projects, shelving new expenditure and implementing hiring freezes during a prolonged period of uncertainty.
"We also have major concerns about the impact Brexit would have on lower-paid sectors which rely heavily on workers from the EU, such as hospitality, healthcare and farming.
"It is difficult to see how an Australian points-based immigration system would meet the needs of businesses in these sectors when British applicants are already in short supply."