A report by KPMG and the Recruitment and Employment Confederation (REC) has revealed a decline in both permanent and short-term staff appointments during July.
At the same time, recruitment consultants reported an increase in the availability of staff, according to the report.
The report suggested that temporary employement was also down.
But although the number of permanent and short-term jobs fell, the rate at which it fell was slightly less in July than in June.
Jobs in engineering, construction, nursing and medical care were the most sought-after, the report said.
Demand for staff in the public sector continued to fall, but demand for workers in the private sector did increase.
Bernard Brown of KPMG said: “Only a few weeks ago there was an audible sigh of relief across the UK’s workforce as official employment figures indicated signs of improvement.
“However, my concern is that any sigh of relief may be mistaken for a groan of exasperation, because the rate at which employers are recruiting has decreased for the second consecutive month, and this suggests that there is still a high degree of uncertainty.”
REC chief executive Kevin Green said: “The UK’s labour market deserves a gold medal for its incredible performance in the face of adversity so far this year. In the last few months, it has defied gravity as unemployment has fallen and jobs grew even while the economy slipped back into recession.
“But this run might be coming to an end as this month’s data shows that permanent appointments have fallen for a second month and temporary employment has seen an eighth consecutive month of contraction.
“However, we have always said that we expected to see ups and downs in the employment figures rather than a continued sustained period of jobs growth.”