A rift has opened up between rival camps of geographers over contentious plans to create a new combined history and geography GCSE to meet the English Baccalaureate (EBac) requirements.
In order to receive an EBac, students are required to obtain a GCSE or IGCSE in either history or geography, as well as English, maths, two sciences and a foreign language.
Fearing that schools will force students to choose between the humanities subjects and not give them the opportunity to take both, the Geographical Association (GA) and the Better History Group think-tank have joined forces to propose the combined GCSE.
But the Royal Geographical Society (RGS), the professional body for geographers, believes the joint GCSE amounts to "substantially watering down" both subjects.
RGS director Rita Gardner said the proposal was "untested, likely to restrict rather broaden opportunities and have the potential to undermine the positive impact of the EBac on geography and history".
She added: "A combined, single GCSE can only be achieved by substantially watering down the range and depth of content, neither allowing pupils to get to grips with the subject nor preparing them for separate study at A-level."
The GA, however, is keen to pursue the joint qualification as an alternative to the existing humanities GCSE, which it says is "lacking rigour".
It proposes that all students take a history module - Parliament and democracy - and a geography module - people and environment - in Year 9, and then decide whether to "major" in one of the subjects or "minor" in both.
GA chief executive David Lambert said: "Realistically, most students will have to choose between the two subjects. Very few schools can offer both, which is a shame.
"We are being bold and opening up a discussion on whether there's an alternative. The outcome we want is to have more children studying both history and geography."
The GA described the humanities GCSE as the "worst solution", characterised by "poor" teaching and with "the level of intellectual challenge diluted".
Better History Group chairman Sean Lang, a senior history lecturer at Anglia Ruskin University, said the two subjects have a "very close relationship".
"We are very much against the idea of integrated humanities," he said. "It's not an academic discipline, it's a compilation of subjects such as history, RE and geography and came about because of economising.
"What's being proposed would be a GCSE that is half history and half geography, and each half would be a coherent course in itself."
But Dr Gardner warned that the plans could "encourage the view that these subjects only need be taught as half courses" and that the proposal could end up as a weakened integrated course, like the humanities GCSE.
She added: "Subject disciplines exist to provide essential knowledge and skills; not for timetabling and administrative convenience."
A Department for Education spokeswoman said: "While the English Baccalaureate will give pupils the opportunity to study a core of academic subjects, it does not restrict their choices or opportunities for wider study. The core of subjects is small enough to allow for that choice."