The number of people claiming jobless benefit jumped unexpectedly in January and at its fastest rate in 6 months, raising fears that an improvement at the end of last year may have been little more than a blip. Figures from the Office for National Statistics on Wednesday showed claimant count unemployment rose by 23,500 last month, the biggest rise since last July. The rise wiped out the declines seen in the previous two months and took the total number of claimants to its highest since 1997, when the ruling Labour party came to power. Economists had been expecting claimant count unemployment to fall for a third consecutive month, by around 10,000. There was better news on the internationally comparable ILO jobless measure, which includes people out of work and not claiming benefit. Unemployment on this broader measure fell by 3,000 in the three months to December to 2.457 million, its lowest since April-June 2009. The ILO jobless rate was steady at 7.8 percent of the workforce, well below the rate of 9.7 percent in the United States and 10 percent in the euro zone