Girlguiding says its own research has suggested almost a third of 11 to 21-year-old girls and young women have missed school or college because of their period.
Isla, also 19, and a member of Girlguiding’s panel of advocates, called the figures “unacceptable”, adding that “giving primary school girls access to tampons and pads will help break the taboo of periods from a young age”.
A Department for Education spokesman said officials would begin talking to school and college leaders on the quantities of sanitary products likely to be needed from early next year, and how best to deliver them.
He said they were likely to be bought in bulk and distributed locally.
Mr Zahawi added: “After speaking to parents, teachers and pupils, we are now extending this to more than 20,000 primary schools so that every young person in all our schools and colleges gets the support they need.”