Retail employment fell 0.4% in the second quarter of this year, equivalent to 3,100 fewer full-time jobs.
The trend worsened throughout the quarter, according to the BRC-Bond Pearce Retail Employment Monitor, falling 0.2% in April, 0.4% in May and 0.7% in June.
It is the first time the monitor has recorded a decline for three consecutive months.
During the quarter the number of retail outlets grew by 4.5%, an additional 743 shops.
Non-food retailers scrapped the most positions as they fought declining footfall and tough trading conditions, with both their full-time and part-time employees working fewer hours.
Conversely, food retailers continued to increase employment.
Retailers expect to cut jobs and hours in the present quarter too, with a quarter of retailers planning on decreasing staffing levels.
58% of the sample indicated that they would keep staffing levels unchanged in the next three months, the same as this time last year.
BRC director general Stephen Robertson said: “Most retailers continue to hold steady and almost one in five still expects to increase jobs, but a growing number are having to limit hours and reduce staff - leaving overall retail employment down on a year ago.
“The split reflects the very different fortunes of retailers selling food - a must-have for customers - and those servicing discretionary and big ticket spending.
“With the latest GDP data showing how weak the recovery is, the Government needs to act quickly. It must implement its Growth Strategy, particularly reducing government-generated costs from regulation, inconsistent enforcement, business rates and new employment law measures.
“Large and medium sized companies need the same moratorium on new regulation as the smallest firms.”