The Turnbull government will pour almost $19 billion extra into school funding over the next decade and embrace David Gonski's needs-based funding model in a major policy backflip that seeks to neutralise one of Labor's key political strengths.

But the opposition will continue to claim the policy high ground by noting the government's commitment was still $22 billion less than Labor has promised to spend on schools over the decade to 2027, and $6.3 billion less over the next four years.