Growth in the UK's services sector slumped to its slowest pace in three years in February, according to a closely watched survey.
The Markit/CIPS purchasing managers index (PMI) score fell to 52.7 in February, down from 55.6 in January. Any figure above 50 indicates growth, but the score is the lowest since March 2013.
It is estimated that the services sector accounts for 75-80% of the UK's entire economy.
Chris Williamson, chief economist at Markit, said: "Survey responses reveal that firms are worried about signs of faltering demand, but boardrooms have also become unsettled by concerns regarding the increased risk of 'Brexit', financial market volatility and weak economic growth at home and abroad."
The index score paints a worrying picture of Britain's economy, adding to weaker data from the manufacturing and construction sectors revealed this week. The manufacturing PMI score fell from 52.2 to 50.8, and the construction index hit an unexpected 10-month low of 54.2.