The English baccalaureate, a performance measure used in school league tables, was introduced too early a report by a committee of MPs has said.
While not a qualification the EBac is designed to measure how many pupils in a school have achieved a grade C or better on core academic subjects, including English, mathematics, history or geography, the sciences and a language.
The measure was introduced in 2010 in addition to a long-used benchmark of the number of pupils who gained A* to C grades in English, maths and at least three other subjects, which could include vocational courses.
In its report the Education Select Committee said that the measure should not have been introduced before the National Curriculum Review was completed.
Conservative MP Graham Stuart, who is chair of the committee, told The Huffington Post UK that the EBac was a "piecemeal" measure. He said:
"If you're going to have a coherent, joined-up system of performance measures, and curriculum measures, and testing and assessment, you have to have to view them all together, not come up with piecemeal measures as was the way the EBac was brought in."
There was evidence that the EBac had left some poorer students behind, which was against the original intent of the policy.
"Any cliff edge performance measure like this will have a tendency for schools to focus on borderline pupils," Stuart said. "And with the EBac those borderline pupils are the more able. As a committee we have repeatedly called for an assessment and accountability regime which gives equal weight to the progress of every child and as it stands the EBac bad risks doing that."
While the committee did not give specific recommendations on which subjects should have been included in the EBac, Stuart said that vocational courses in particular had been affected in some schools.
"It is parents, pupils and schools who are in the best position to judge what subjects a pupil should sit for their GCSEs," he said. "We have heard from industry concern about some subjects being excluded and devalued which could have an impact on the skills that young people will bring to the workplace. We've also heard concerns about a particular Latin qualification that isn't included in the EBac which could lead to a big drop in the amount of Latin teaching in our schools."
The National Union of Teachers welcomed the report. Christine Blower, General Secretary of the NUT, said:
"The NUT welcomes the Select Committee’s findings that the English Baccalaureate should only have been introduced after proper consultation with stakeholders."
“The English Bac, by focusing on such a narrow range of subjects, may prejudice the National Curriculum review and should not have been introduced before this had taken place. It has already impacted negatively on the uptake of other subjects in schools such as the arts and humanities, with schools being forced to focus on this new narrow range of subjects."
Nick Gibb, the schools minister, said: “we believe very strongly that all children have the right to a broad and balanced education that includes English, maths, science, a language and a humanity."
"Just eight per cent of children eligible for free school meals were entered for the EBac subjects last year compared to 22 per cent overall. Closing the attainment gap between children from wealthier and poorer backgrounds is a key objective of the government."