New rules aim to create a level playing field for school admissions. But secondary school headteachers say the regulations are too complex, over-prescriptive and in parts unworkable. They fear they will increase bureaucracy, opening the floodgates for admissions appeals.

Admissions are being revised in line with the Education and Inspections Bill - the new codes on admissions and appeals are out for consultation.

But heads are worried about how this will affect school management. The previous code was for guidance, but its successor sets out nearly 180 pages of mostly mandatory requirements.

One key issue is a tension between promoting social equality while enabling more parents to gain a place at their school of choice. The Association of School and College Leaders says it is not clear which should take preference.

“Which is supposed to win if it comes to the crunch?” said Martin Ward, deputy general secretary of the ASCL. “Are we to say to a parent, ‘I’m sorry, your child would have got into this school, but in the interests of equity we have let somebody else in from a different group?’”

A requirement to balance a secondary’s intake based on criteria including gender, ethnicity, home location and social class will increase bureaucracy, he said. For over-subscribed schools, it will boost the already high number of admission appeals, taking leaders away from the job of running the school. Heads are also worried that the code appears to disadvantage secondary moderns - it says there must not be “first preference first” in an area where there is selection.

Measures to ensure that costs, such as expensive school uniforms or school trips, do not put parents off also pose potential problems for schools. The code says schools which have a uniform that is “more expensive than the national average” should ensure that no family feels unable to apply.

But it does not define what that average is, and the ASCL is concerned that this will mean more data collection. Stipulations about the cost of school trips could further put schools off providing them. The association warned that requirements to ensure extended opportunities are available to all children could result in schools in poorer areas not being able to balance their books.

Mike Griffiths, head of Northampton school for boys, an oversubscribed 11-18 comprehensive, said his school already has 100 admission appeals a year.

“I think there’s a grave danger that there’s going to be a huge clogging up of legal processes, challenges, ombudsmen, adjudicators and others, with people basically disappointed that they didn’t get in,” he said.

Christine Wright, head of St Wilfrid’s RC College in South Shields, said her school already admits more than 25 per cent of non-Catholic pupils. She said she was concerned that the new code amounted to social engineering.