Mr Shearer applauded the "gold standard" programme for its 80 per cent-plus success rate and said under Labour it would become universally available.
But only 59 per cent of low-decile schools had access, compared with 73 per cent of high-decile schools, he said.
Currently, about 14 per cent of 6-year-olds are enrolled in it nationally.
Labour planned to extend the programme to all schools, making it available to about 5000 more 6-year-olds each year, costing an extra $20 million annually. The party has also proposed a similar maths recovery programme for 7- and 8-year-old students and has pledged to provide free food for all 650 decile one to three schools at an annual cost of up to $19 million.
Mr Shearer yesterday justified the policies, which received backing from the New Zealand Educational Institute and Kids Can Charitable Trust - an organisation which provides breakfast in schools.
"If kids can't get to school and be ready to actually learn then they're not going to learn," Mr Shearer said.
"Fifty per cent of our prison population are functionally illiterate so we've got to really make an effort to make sure that those kids don't slip behind."
And though the National Standards grading system would not be scrapped under Labour, individual schools could opt out of them if they wished.
NZEI president Ian Leckie said under the current system too many students were missing out on reading recovery, adding to New Zealand's literacy woes.
Kids Can chief executive Julie Chapman said the organisation's food programme could be used in low decile schools under the free food proposal, but it should be aimed at those most in need.
Labour's plans:
Extend reading recovery to all schools, making it available to 5000 more 6-year-olds a year. Cost: $20 million.
Make National Standards optional.
Introduce individual report cards for each school.
One meal a day for children in decile 1 to 3 primary and intermediate schools.
