More than 19,000 pupils will lose money towards the cost of their school uniforms after Leeds City Council decided to cut its funding by £400,000.
Since 1992, low income families have received annual vouchers of £20 or £30 for primary or secondary school pupils.
In September, only 4,500 pupils will automatically qualify for the financial help compared to 24,000 in 2005/6.
The council said letters had been sent to the 12,000 households affected, informing them of the change.
Any parent or carer with a child entering or in reception or year 7 classes who has an annual income of less than £14,155 can apply for the benefit, which this year will increase by £7.50 and be paid by cheque instead of vouchers.
Poorest families
Leader of the council Mark Harris said the council needed to support investments, including a new children's services team, to champion children and put them at the heart of its services.
"Unlike many local authorities, we have once again committed funding to a scheme which helps low-income families buy their children's school uniform," he said.
But Kate Green, chief executive of the Child Poverty Action Group, said the decision would result in many parents on tight budgets struggling to buy new uniforms for their children.
"For a relatively small financial saving, Leeds City Council's decision is a huge blow to thousands of the city's poorest families who rely on this support," she said.
"We hope the Council will think again and restore annual school uniform grants for those who need them.
"As any parent knows, you don't just buy uniforms for growing children in reception and year 7, you need to buy costly school clothes every year."