Around two million of the lowest waged employees do not even qualify for statutory sick pay, because their earnings fall below the qualifying income threshold.
The new sick pay arrangements do not apply to those without an employment contract, such as independent contractors and the self-employed, or to anyone who earns less that £118 a week.
New measures must be introduced immediately to limit the rise in unemployment, and cushion the income shock for those who will unavoidably lose their jobs.
Citizens Advice is calling for measures to ensure that vulnerable people and low-income families are not pushed into financial hardship as a result of the outbreak.