The UK's economy grew at its slowest annual pace since 2013 in the three months to June, according to revised official figures.
Gross domestic product (GDP) grew by 1.5% from a year earlier, the Office for National Statistics (ONS) said, down from an earlier estimate of 1.7%.
However, the quarterly growth rate remained unchanged at 0.3%.
Separate figures from the ONS indicated that the UK's key service sector contracted by 0.2% in July.
The ONS said a key factor behind the fall was a drop in activity in the film industry following a particularly strong June.
In the three months to July, the service sector grew by 0.5% compared with the previous three months, which the ONS said was the highest quarter-on-quarter growth in 2017 so far.
ONS figures also showed that the UK's current account deficit widened to £23.2bn in the April to June quarter compared with a deficit of £22.3bn in the previous quarter.
The weaker-than-expected growth and service sector figures sent the pound lower, as they appeared to cast doubt on whether the Bank of England would increase interest rates later this year.
Recently, several Bank policymakers have hinted that rates could rise soon, and earlier on Friday the Bank's governor, Mark Carney, told the BBC he expected they would increase in the "relatively near term".
However, Chris Williamson, chief business economist at IHS Markit, said the latest ONS figures suggested that rates should not rise from their present record low of 0.25%.
"From a recent historical perspective, since the Bank of England's independence, it would be unprecedented for the central bank to tighten policy with the data pointing to such anaemic economic growth," he said.
"However, policymakers continue to fuel expectations that interest rates will rise soon in response to higher-than-expected inflation."
Darren Morgan, head of gross domestic product at the ONS, said: "There was a notable slowdown in growth in the first half of 2017.
"The often buoyant services sector was the only area to grow in the second quarter, mainly due to increases in computer programming and retail.
"Household spending growth continued to slow in the second quarter. However, revised figures show business investment grew more strongly than previously estimated."
The ONS said business investment rose by 0.5% in the second quarter of the year to £45.7bn.