League tables showing how schools performed in GCSEs highlight the "stark inequality" of the British education system, a teachers' union claimed.

The National Union of Teachers spoke out in the wake of this year's results showing 160 of the country's top-performing state schools were selective.

Of the remaining 40, 26 are voluntary-aided such as faith schools, three city technology colleges and one an academy, all of which benefit from extra funding.

Only three are ordinary comprehensive community schools serving the local area and all of these existed in affluent suburbs, such as Arden School in Knowle, south Solihull.

Roger King, head of the Birmingham branch of the NUT, claimed the continued existence of grammar schools in the city was a major cause of inequality locally.

"The grammar schools in Birmingham damage the educational standards of children on the whole," he said.

"Without them, schools that are currently struggling would be doing better. Studies show where you have schools of mixed ability all schools do better than where you have schools that hive off some of the more able children.

"I think if you got rid of the grammars you would see rising standards in all other schools. They are representative of the inequality of education. They are elitist. They are selective and they are funded at a much higher rate than ordinary schools."

Birmingham has seven grammars: five within the King Edward VI Foundation - which also includes the city's fee-paying King Edward boys' and girls' schools - plus Handsworth Grammar and Bishop Vesey's.

Mr King claimed most parents had a "mistaken" belief their child stood a chance of getting into one when in fact only some five per cent managed to make it.

"They are predominantly middle class and from better off families so there is that built-in disadvantage which has damaged Birmingham's education system, but there has never been a Cabinet Member or chief education officer who has had the courage to tackle it."

Ann Green, head of Arden School, also criticised grammars.

"It is not a philosophy I agree with. I believe you make schools sit at the heart of the community. The effect of selection on the schools around them can be extremely demoralising.

"You only have to take 30 children out of a comprehensive and you take 15 per cent off its five A to Cs. That means it looks under-achieving."

However, Elspeth Insch, head of the selective King Edward VI Handsworth School, claimed the impact of grammars was exaggerated.

"Only eight per cent of Birmingham children are in grammar schools," she said.

"If you distributed them across every school in the city it averages one child per class so the negative effect is very little."

However, Ms Insch added: "There is regretably a link between affluence in the family and attainment at age 11. In other words, kids at posher schools do better. That means the schools in Birmingham that are most heavily creamed by the grammars tend to be in affluent areas and they tend to be the schools getting good GCSE results."

Ms Insch claimed her school was one of the most socially and ethnically diverse in the city.

"If the population of Birmingham is divided into socio-economic quintiles, a fifth of my pupils come from each of these.

"You couldn't have a school more socially and ethnically diverse."

Ms Insch criticised parents who intensely coached their children to pass the 11-plus, but admitted it was unfair some youngsters were disadvantaged by not knowing what to expect in the test.

She added: "If I had my dream it would be that every child irrespective of its social background and family circumstances could have an absolutely first rate education in a first rate school with first rate support from their family.

"Does that happen in the city now? No it doesn't. Clearly there are schools that are better than others.

"But I suspect these differences are less than when I came into teaching and I think in time they will even out."

Birmingham's director of children's services Tony Howell said the authority was keen to develop a "diversity in the range of secondary schools" of which grammars were a part.