Britain's National Living Wage, which applies to those aged 21 and older, is expected to rise to about £13.20 an hour from £12.71 — an increase of 3.9%.
According to report in The Times, the National Minimum Wage, which applies to those aged 18, 19 and 20, will rise broadly in line with the rate for older workers to around £11.27 an hour from £10.85.
If confirmed in Wednesday's budget announcement, those increases would take effect in 2027 and end a trend seen in recent years in which the minimum rate for younger workers has increased by more than that for older workers.
Britain's minimum wage is one of the highest among advanced economies as a share of median earnings, following efforts by successive governments to lift it to two-thirds of median hourly pay.
Some analysts and employers have previously pointed to the rate payable to younger workers as a cause of increasing youth unemployment.
In March, the government tweaked the commission's remit to give it more scope to take labour market conditions into account when setting the minimum wage for 18- to 20-year-olds.
In April, the Low Pay Commission, which advises the government on minimum wage rises, said the National Living Wage would probably need to increase by around 3.7% in 2027 to £13.18 an hour to keep up with how it expected average pay to rise.