UK unemployment rose by 114,000 between June and August to 2.57m, a 17-year high, according to official figures.
The Office for National Statistics (ONS) said the unemployment rate also increased to 8.1 per cent.
The number of Britons claiming unemployment benefit rose by 17,500 in September, official data showed on Wednesday. Analysts had forecast a rise of 25,000.
However, the Office for National Statistics said the number of people without a job on the wider ILO measure jumped by 114,000 in the three months to August to 2.57m, the highest total since October 1994.
The jobless rate ticked up to 8.1 per cent, the highest since October 1996, compared with forecasts for a reading of 8.0 per cent.
The Bank of England launched a fresh round of stimulus last week, pumping an additional 75 billion pounds into the economy in order to prevent a renewed recession. BoE economist Spencer Dale told Reuters in an interview the economy was likely to weaken further in the final quarter of this year.
The ONS said pay increases slowed in the three months to August, in a sign that wages were unlikely to fuel inflation.