The British economy grew 0.2% in the final quarter of 2018, compared to the previous three months, according to data published Monday.
The rate of expansion for the full year was 1.4%, down from 1.8% in 2017.
Economists said that uncertainty over Brexit was a major factor in the poor performance, with business investment falling for the fourth consecutive quarter.
With less than 50 days to go before Brexit, Prime Minister Theresa May has still not identified an exit proposal that is acceptable to both the European Union and UK parliament.
Paul Dales, Capital Economics' chief UK economist, gave his take in a note to clients:
As the drag on growth from Brexit uncertainty is only going to be bigger in [the first quarter], there's little hope of a rebound early this year.