Britain has been slower than other European countries to lay out plans to reopen its economy. Wednesday's PMI data showed British construction suffered its sharpest decline on record in April, more than twice as large as the previous month, even though general building work was not included in the government-ordered lockdown.
The pound did not move significantly when the data was announced at 0830 GMT. But between around 0720 GMT and 0835 GMT, cable fell 0.7%, hitting a 12-day low of $1.2359, a move which analysts said had no specific trigger.
Like many currencies, the pound is mainly subject to changes in global risk appetite, said Thu Lan Nguyen, senior FX strategist at Commerzbank. "We had a phase in March particularly where more pound-specific factors were playing a role, but since April at least it's moving more or less with global market sentiment."
The construction PMI showed a steep monthly decline, falling far below even the lowest estimates from economists polled by Reuters. Michael Hewson, chief market strategist at CMC Markets, said that the extent of the economic damage from coronavirus and the scale of a possible recovery were still unknown. "The data was poor - an awful lot worse than an awful lot of people had predicted, which reinforces the fact that it's very difficult to predict the levels of PMIs going forward," he said.
Against a stronger dollar, the pound was last at $1.2363, down 0.6% since New York's close. Versus the euro it was down around 0.2% at 87.345. The Bank of England will meet on Thursday and attempt to quantify the economic impact of lockdown measures, which official budget forecasters predict could push Britain's economy into the worse collapse in 300 years.