Britain's unemployment rate rose by more than expected to 4.5% in the three months to August, up from 4.1% in the three months to July, even before the end of the government's broad coronavirus job protection plan.
Economists polled by Reuters had expected the unemployment rate to rise more slowly to 4.3%.
The number of people in employment fell by 153,000 in the June-to-August period compared with a median forecast for a fall of 30,000 in the Reuters poll.
However, separate tax office data showed the number of staff on company payrolls rose by a monthly 20,000 in September, slightly reducing the total number of job losses by that measure since March to 673,000.
The Bank of England has forecast that the unemployment rate will hit 7.5% by the end of the year as the government scales back its 50 billion-pound ($65 billion) job protection scheme and replaces it with a smaller programme in November.
BoE Governor Andrew Bailey on Monday repeated his warning that the economy could prove weaker than the central bank's forecasts.