SCOTLAND'S biggest teachers' union yesterday voiced grave concern that access to education still depended on ''who you are and where you live'', writes Raymond Duncan.

The criticism by the Educational Institute of Scotland came as the union launched a major survey which, for the first time in recent years, has analysed in detail the impact of socio-economic factors on educational performance.

Highlighting evidence in the report that every year in Scotland around 20,000 children in families were accepted as homeless by councils, a senior EIS official said that was the equivalent of the population of 50 to 60 schools. ''That is a horrifying thought,'' said Mr George MacBride, convener of its education committee.

The union's general secretary Ronnie Smith told a press conference in Edinburgh to unveil the findings of the survey that ''rampant inequalities'' had bedevilled the country's education system for decades. ''Poverty must not be a barrier to educational opportunity for young people,'' he declared.

Mr Smith said the Government had to tackle poverty as a priority if it was to achieve its own aims of improving educational performance.

The survey, Poverty and Education - Breaking down the Barriers, which has been sent to Scots education Minister Brian Wilson, is the result of EIS consultation with researchers and academics.

It includes work on poverty and education in Glasgow carried out by Strathclyde University Professor Michael Pacione, showing that geographical difference - where people lived - was still important in achieving a good education.

Mr Smith said evidence showed that in recent years inequalities in education had increased rather than decreased. The depth of the problem was indicated by ''appalling'' statistics showing that about 20% of Scottish pupils were entitled to free school meals with the ''even grimmer'' Glasgow figure of 40%. Approximately 25% of children lived in households dependent on income support.

''To expect schools alone, through setting arbitrary objectives, to compensate for such levels of disadvantage is neither fair nor realistic,'' said Mr Smith.