Markit Economics released its manufacturing purchasing managers' index (PMI) for the U.K. on Tuesday. The Markit/Chartered Institute of Procurement & Supply manufacturing PMI for the U.K. dropped to 49.2 in April from 50.7 in March, missing expectations for a rise to 51.2. It was the lowest level since February 2013.
March's figure was revised down from 51.0.
A reading above 50 indicates expansion, below indicates contraction.
The drop was driven by declines in output, new orders, employment and stocks of purchases.
"Manufacturing production is now falling at a quarterly pace of around 1%, and will likely act as a drag on the economy again during the second quarter and putting greater pressure on the service sector to sustain GDP growth," Markit's Senior Economist Rob Dobson said.
"Manufacturers are emphasising slower domestic demand growth and declining new export orders as the key weaknesses they are facing, amid rising uncertainty about the global economy, the oil & gas industry, retail sector and the EU referendum," he added.