The BDO Employment Index, which predicts companies' hiring intentions in three months' time, rose from 108.8 in June to 109.6 in July, surpassing its pre-crisis peak to reach its highest level since 1998.
Accountancy firm BDO said July's gains were driven by the uptick in hiring intentions among services firms in particular. Inflationary pressure is likely to be a key reason behind the longstanding levels of confidence among businesses, the group said.
Read MoreUK productivity 'abysmal'—but economy growing well
Last week, the National Institute of Economic and Social Research (NIESR) said it expected the U.K. economy to grow by 3 percent this year, up from 1.7 percent in 2013. This is slightly less than the 3.2 percent forecast by the International Monetary Fund.
U.K. economic growth has been 0.5 percent or more per quarter for the last six consecutive quarters—nearly twice the rate seen between 2010 and 2012. The labor market also continues to improve, with total employment now more than 4 percent higher than it was at the start of 2008, NIESR said.
"The good news is that the unprecedented growth we've seen in U.K. employment this year looks set to continue, providing this year's university graduates with a welcome dose of good news in terms of job and salary prospects," said Peter Hemington, partner at BDO.
Read MoreS&P upgrades outlook for UK economy
"However, we're hearing that services firms are beginning to echo manufacturers in voicing their concerns over a shortage of skilled workers and some construction businesses are already turning business away due to a lack of trained staff. This could bring the stellar growth we're enjoying in the wider economy to a grinding halt if the trend becomes entrenched," he added.
Follow us on Twitter: @CNBCWorld