Sterling fell over one percent in American trade off December 4 highs against the dollar, following earlier data from Britain and the US today.
As of 04:50 GMT, GBP/USD declined 1.20% to 1.2587, with an intraday high at 1.2773, and the lowest since December 14 at 1.2582.
Earlier UK data showed the manufacturing PMI up to 54.2 from 53.6, easily beating estimates of 52.5.
Otherwise, earlier US data showed the Marki manufacturing PMI down to 53.8 in the final reading from 53.9 in the preliminary one, below November's 55.3 reading.
The US ambassador to the UK ruled out in earlier remarks a bilateral trade agreement with Britain in case the UK Parliament approved the current organized Brexit deal with the EU.
He believes the current conditions in the agreement will be hurdles against a deal with the US, while also noting how they reflect a defeatist position from the British standpoint.