The number of children being taught at Welsh-medium primary schools last year rose by only 75 extra pupils, new Assembly government figures reveal But Welsh-language parents' pressure group Rhieni Dros Addysg Gymraeg (RHAG) has been quick to blame the apparent stagnation in the sector on a lack of provision.
It says that space at overcrowded schools is fast running out.
Its views are backed by the findings of a survey by Newport council that shows 31 per cent of parents in Newport county would probably send their children to a Welsh-medium school if there was one less than two miles from their home.
Overcrowding is seen as a particular problem at Welsh-language schools in Cardiff, while English-speaking peers suffer from surplus places. The statistics show there were 52,867 pupils in 458 Welsh-medium primaries in 2006.
The proportion of primary pupils taught in classes where Welsh is predominant has increased from 19.6 per cent in 2005 to 20.1 per cent in 2006.
At secondary level there has been a rise from 14.8 per cent to 15.2 per cent. The proportion of Year 7 pupils being taught Welsh as a first language increased from 15.5 per cent in 2005 to 16.7 per cent in 2006.
Tim Pearce, of RHAG, said: "Until there are more places, the sector cannot grow properly."
He called on local education authorities to improve transport to Welsh-medium schools and ensure that it remains free.
"A parent who would prefer their child to have such an education may opt for the local English school because the Welsh one is much further away,"
"The more Welsh-medium education is available, the more people choose it."
In Cardiff, four new Welsh-medium starter classes will run from September.
Under its Welsh-language document Iaith Pawb, the Assembly government wants 26 per cent of the population to be Welsh-speaking by 2011.
Plaid Cymru AM Owen John Thomas said the annual intake into Welsh-medium schools in Newport could be doubled, such is the interest from parents. And he said Newport LEA should provide more places.
The council's research found that 16 per cent of parents were "very likely"
and 15 per cent were "quite likely" to choose a Welsh-medium school if they had the opportunity.
Newport's only Welsh-medium secondary school, Ysgol Gymraeg Casnewydd, is in the south-east of the city but most of the demand is from the north and north-east.
Mr Thomas said: "Here is an opportunity to double the annual intake into Welsh-medium education in Newport from 60 to 120."
Geraint Davies, of teachers' union the NASUWT Cymru, said: "In the past 10 to 15 years, the growth in Welsh-medium education has been constant."
An Assembly Jspokesperson said: "Where more Welsh-medium places are needed, the minister expects LEAs to develop proposals to establish new schools or expand existing provision."