The Albanese government admits it needs to rein in the National Disability Insurance Scheme after revealing its cost will blow out by almost $9 billion over the next four years, putting further pressure on the already-ravaged federal budget.

With the policy now among the top five demands on spending, despite being less than a decade old, next week’s budget will forecast its annual cost to surpass $50 billion by 2025-26. This is about $20 billion more than the Productivity Commission estimated in 2017 when the scheme became fully fledged.