The Conservatives have said that "education vandalism will be the lasting legacy of the prime minister and Bridget Phillipson".
It follows the educational secretary announcing the biggest shake-up of the curriculum in England in a decade.
Changes include cutting the overall volume of exams at GCSE level by 10%, introducing mandatory citizenship lessons in primary schools, and lessons on AI and being able to identify disinformation.
Primary pupils will also learn more about the fundamentals of money.
Reacting to the curriculum review, Laura Trott, the shadow education secretary, said: "Labour's idea of boosting social mobility is to teach primary school children about climate change instead of making sure they can read, write and add up properly.
"These reforms will mean children moving towards an 'enrichment entitlement' and see fewer children studying history and languages post-14.
"This will leave children with a weaker understanding of our national story and hide standards slipping in schools."
The Liberal Democrats are also critical of the changes, with the party's education spokesperson, Munira Wilson, saying that the "fiscal and practical feasibility of these changes have not been addressed".
She added: "Headteachers, who are already having to cut their budgets to the bone will be asking one simple question - 'how am I supposed to pay for this?'
"Liberal Democrats are calling for Labour to be honest with schools. To admit that without a costed plan and proper workforce strategy, these reforms will stretch teachers even further and fail our children."
The Lib Dems admitted that it's a "welcome step" for Labour to embrace "a broader curriculum with a clear focus on arts and digital education".
But Wilson said scrapping "instead of broadening the Ebacc is not the right move".