Theresa May faces a backlash from Tory MPs after £240m was devoted to an expansion of grammar school places in the Autumn Statement.
One Conservative told The Independent the much needed cash should be refocused on ensuring high-quality leadership in schools in general.
Others said they were "taken aback" when Chancellor Philip Hammond announced the money would be set aside for the plan.
The money to increase places at existing schools comes as Ms May is still consulting on her proposals to open completely new grammars, a process some felt should be completed before any expansion of selective education occurs.
Mr Hammond said £60m has been earmarked every year to 2020/21 to expand existing grammar schools. The consultation on Ms May’s plan to lift the ban on opening new grammars finishes on December 12.
New Forest West MP Desmond Swayne told The Independent he supported lifting the ban on grammar schools, because in some areas there may be demand, but he added: "However, my belief is fundamentally that our problems are with a shortage of high calibre leadership in schools.
"If you look at the good schools in the most deprived areas you can have outstanding schools where you have outstanding leadership, that has got to be our main effort.
"If I had £240m, I’d be inclined to make sure I was addressing that need before setting up new grammar schools."
Ms May backed the opening of new grammar schools in September, something currently banned by law, arguing that they would boost the life chances of poor pupils and highlighting how the current system leads to "selection by stealth" based on parents' wealth and ability to buy houses near the best schools.
But the plans were met with opposition from the education establishment, opposition parties and enough Tory MPs to create a problem for Ms May given her small Commons majority.
One senior Tory said: "A number of colleagues were really taken aback that money is already in the scorecard for an expansion of places, given there is a consultation related to the same issue that is still happening.
"In the Commons Justine Greening was saying ‘there is a consultation, let’s ask the question and see what people say’. Ministers have been careful to say they will listen. Well, there are very few voices in the education sector who are in favour of more grammar school places."
A spokesperson from the Department for Education said: "We want all children, whatever their background, to have access to an education that will unlock their talents. That’s why we are consulting on proposals to scrap the ban on new grammar schools and make more good school places available, to more parents, in more parts of the country."
The spokesperson added: "We have also protected the core schools budget so that, as pupil numbers increase, so will the amount of money for our schools – in 2016-17 that will total over £40 billion, the highest on record."
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