British businesses' confidence in the economic outlook has continued to improve from very weak levels, a survey for January showed, extending gains since finance minister Rachel Reeves' November budget imposed fewer immediate tax rises than feared. The Institute of Directors said on Monday that optimism about prospects for the UK economy remained deep within negative territory, but it rose to -48 in January from -66 in December and was the highest level since last May. It hit an all-time low of -74 in September for the series, which started in 2016.