The most likely impact is lower employer contributions overall for staff pensions by those paying in more than the minimum, says the former Pensions Minister.
Salary sacrifice schemes allow workers to take a supposed 'pay cut', with the money paid into their pension or put towards some other benefit like childcare instead.
Nearly two in five savers say they will cut back on pension contributions if there is a salary sacrifice crackdown in the Budget, new research reveals.
Rachel Reeves is said to be considering a £2,000-a-year cap on how much salary can be sacrificed into a workplace pension without incurring National Insurance costs.