The highest earners have been the biggest winners from the economic recovery so far, according to figures compiled for Labour.
Analysis by the House of Commons Library found the top 1% - around 300,000 people - increased their share of national after-tax income from 8.2% in 2012-13 to 9.8% last year.
Meanwhile, the bottom 90% - some 27 million people - saw their share fall from 71.3% to 70.4%.
Shadow chief secretary to the Treasury Chris Leslie said the analysis - based on data from HM Revenue & Customs - showed ordinary workers were being "left behind".
"David Cameron and George Osborne are trying to claim the cost-of-living crisis is over, but these official figures expose what's really happening under the Tories," he said.
"With the help of a huge tax cut from this government the very richest are feeling a recovery, but everyone else is being left behind as growth finally returns.
"What we need is a recovery for the many, not just a few at the top.
"That's why we need to reform our economy to mend the broken link between the wealth of the nation and the living standards of hardworking Britain.