The IMF on Monday downgraded its U.K. economic growth forecast by 0.3 percent.
The cut came following a weaker-than-expected performance in the first three months of 2017 and it is the first since last year's EU referendum.
According to the new estimate, the British economy will grow by 1.7 percent this year but not two percent as predicted in April.
The IMF did not change its U.K. growth forecast for 2018, leaving it at 1.5 percent.
These latest figures are in contrast to major eurozone countries like Germany, France, Italy and Spain as the IMF raised its growth expectations in those states.
An IMF forecast that the global economy will grow by 3.5 percent in 2017 and 3.6 percent in 2018 remained unchanged.
The U.K. is expected to leave the EU in 2019, after a 44-year membership of the bloc.
