Britain's rapid growth rate will become "ingrained" and more balanced, the European Commission said on Monday, as two separate reports suggested the strong rate of expansion was likely to continue.
The EC now expects the UK economy to grow by 2.7% in 2014, compared with a forecast of 2.5% three months ago, the Telegraph reports.
It also upgraded its forecast for 2015 growth to 2.5%, from a previous estimate of 2.4%.
"Growth is expected to become firmly established... and its composition is expected to broaden," the EC said in its spring forecast on Monday.
The upgrade means Britain has cemented its position as one of the fastest growing economies in Europe - above Germany, which the Commission believes will grow by 1.8% this year, and France, which is predicted to grow by just 1%.
Only Sweden - which is forecast to grow by 2.8% this year - is predicted to expand at a faster pace among the advanced economies.
The strong rate of expansion has put Britain on course to be the fastest growing country in the G7 this year, according to the International Monetary Fund (IMF).
PwC, the accountancy firm, also lifted its forecasts for the UK economy yesterday. It now believes Britain will expand by 2.8% this year, up from a forecast of 2.6% last month. This puts its growth rate above America, Germany, Japan and Australia.
The EC's forecasts came as a survey by the Institute of Chartered Accountants in England and Wales (ICAEW) showed UK business confidence for the second quarter touched a record high, with respondents expecting almost half a million new private sector jobs to be created in the next 12 months.