Some 1.47 million people were out of work in the three months to December, an increase of 46,000.
However, Norway believes that the marginal change is well within the margin of error.
The number of non-UK nationals from outside the European Union working in this country fell by 68,000 to 1.17 million in the quarter to last December compared with the previous year.
However, the number of people in work grew by less than expected, rising by 88,000, about half the consensus forecast in a Reuters poll of economists.More news: Police suspect Benjamin Netanyahu associate of trying to bribe judge
The ONS attributed a rise in unemployment to fewer economically inactive people - those neither working nor looking for a job. They may also fuel speculation that the Bank of England could raise interest rates again as early as May after policy makers said the Brexit vote had lowered the pace the economy can grow without fanning inflation.
However, the claimant count fell by 7,200 last month to 823,000, said the Office for National Statistics.
The number of people in work fell for the first time since August 2016.
Britain's unemployment rate has risen for the first time in 16 months, official data showed Wednesday, in a sign that Brexit uncertainty is feeding into the wider economy.More news: Russian Federation urges U.S. not to play with fire in Syria
United Kingdom unemployment increased unexpectedly at the end of past year but wage data was mixed, which may stoke some further speculation about the Bank of England's likely path for interest rate hikes. Including bonuses, the rate was unchanged at 2.5 percent.
It said average weekly earnings in the three months to December excluding bonuses were up 2.5 percent on the previous year.
That was still weaker than the 3.0 percent reading of British consumer price inflation for December and the ONS said wage growth in real terms dropped by an annual 0.3 percent over the fourth quarter. In midday trading, the pound was 0.5 percent lower at $1.3921.
"This is the sharpest increase in the unemployment level the ONS has seen in nearly five years", said Matt Hughes, a senior statistician from the ONS.More news: Thank George and Abe for day of leisure
Economist Ruth Gregory at Capital Economics said it was a "strong set of labour market figures should dispel concerns that the recent weakness was a sign of things to come".
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