The pound slid in morning trading after official figures showed economic growth in the second quarter had been revised down to 1.5 per cent, its worst annual growth rate since 2013.
The figure was revised down from the original estimate of 1.7 per cent. On a quarter-on-quarter basis, growth stuck at 0.3 per cent.
The pound dipped 0.4 per cent against the dollar on the news, to $1.3386, and 0.5 per cent against the euro, to €1.1349.
The news came as more figures showed the UK's current account deficit widened to £23.2bn, or 4.6 per cent of GDP, in the second quarter, up from £22.3bn, or 4.4 per cent of GDP, in the first quarter.
However, the figures also showed the total trade deficit had narrowed to £6.5bn in the second quarter, largely thanks to increased exports of trade in goods.
“Fresh economic growth estimates from the Office for National Statistics confirm that the first six months of 2017 saw the weakest start to the year since 2012," said Chris Williamson, chief business economist at IHS Markit.
“Services was the only part of the economy to expand in the second quarter, according to the official data. Services grew 0.3 per cent but industrial production fell 0.3 per cent, construction sank 0.5 per cent and agriculture saw a 0.1 per cent dip in output.
"Worryingly, separate monthly data on the services economy showed output dropping 0.2 per cent in July, adding to expectations that the sluggish pace of economic growth expansion looks to have persisted into the third quarter."