Healey, delivering his first Budget, said he wanted to avoid an investor exodus from the UK, according to reports. The decision follows warnings that higher CGT could cost the government money if wealthy individuals leave the country or defer selling assets, as reported by the Times.
The chancellor has previously indicated his aim to make the UK a "country of wealth creation", with policies that lift confidence, investment and profit.
Some prominent Labour figures had pushed for equalising CGT with income tax rates. Defence Secretary Wes Streeting called for a "wealth tax that works" in May, and First Secretary of State Louise Haigh had suggested capital gains should rise to be closer to income tax before Andy Burnham became prime minister.
However, Lord Jim O'Neill, former Goldman Sachs chief economist and adviser to Burnham, warned that raising CGT would send "the wrong message to business". Healey had already ruled out levelling the two tax rates, according to the Financial Times.
In a pre-Budget speech, Tory leader Kemi Badenoch is expected to urge the government to drop its spending plans and reduce borrowing.