British employers increased their spending on temporary staff at the weakest rate in more than six years and hired fewer permanent staff, recruiters said, suggesting Britain's robust labour market will weaken.

Retail and construction saw the biggest fall in demand for staff while nursing and computing remained strong, the Recruitment and Employment Confederation (REC) said in its monthly report.

"Recruiters are reporting that demand for staff is slowing and their clients are reducing business activity on average," REC chief executive Neil Carberry said.

Accountants KPMG, who sponsor the report, blamed Brexit uncertainty. Unlike the rest of Britain's economy, the job market has performed strongly since the Brexit referendum in 2016. Unemployment fell to its lowest rate since 1975 at 3.8% in the first quarter of 2019, official data has shown.