Speaking at the Royal National Mod in Inverness last week, Mr Wilson welcomed research findings that showed 143 Gaelic-speakers would be willing to take conversion courses to enable them to teach through the language.

The report, commissioned by HMI from the Leirsinn Research Centre at the Gaelic college on Skye, said training opportunities would be the key determining factor for many teachers. This would have to include enhancement of their own Gaelic competence as well as competence in teaching within bilingual classrooms and in differentiated learning.

Mr Wilson, who is also Minister for Gaelic, immediately indicated he would be proposing a training scheme to the education authorities that would start next year. He said: “If we can make it straightforward for Gaelic-speaking teachers to convert to Gaelic-medium competence, the prospects for expansion in both primary and secondary sectors will be greatly enhanced.”

But councils are mostly lukewarm in their support for Gaelic at a time when they are facing further severe cuts in sensitive areas. They have also taken issue with the training approach suggested by the Government.

The Scottish Office has proposed a 50-day in-service course for Gaelic-speaking secondary teachers at a cost of Pounds 13,000 per head, of which half would be absence cover. The Leirsinn survey found that 51 of the 143 teachers expressing interest in a conversion course were in secondary schools - although only half were “very interested”.

Councils believe, however, that a 50-day course is excessive, particularly since training teachers in the primary modern languages initiative takes only 25 days. The Scottish Office estimates that it would cost Pounds 300,000 to train 20 teachers next year but the authorities have challenged that too.

They can expect to find themselves under continued pressure, however, since Mr Wilson will argue that lack of available teachers and an absence of training can no longer be used as excuses to hold up the expansion of Gaelic-medium provision.

These were also a reasons cited by HMI for recommending to the previous government that extending Gaelic-medium teaching into secondary schools was neither “desirable nor feasible”. Mr Wilson has now reversed that position.

Two councils have made clear in the past week their reluctance to go along with any Gaelic expansion, especially if they have to pay for it. A report to North Lanarkshire’s education committee prefers the HMI approach of Gaelic culture courses in secondary schools to subject teaching in Gaelic. A reply to the Scottish Office proposals states that this met “the aspirations of local parents. There are too few pupils and too few teachers, even with training, to support a core curriculum in Gaelic. The provision would have financial implications impossible to support from the mainline budget.”

North Lanarkshire also points out that the existing Scottish Office specific grant for Gaelic education, running at just over Pounds 2 million this year, does not meet existing needs. Training support would therefore have to be found from new money.

Edinburgh has told parents that it cannot give a guarantee to continued expansion of the 58-pupil Gaelic-medium unit at Tollcross primary because its education budget is Pounds 5 million overspent. “It is not possible for our council to commit itself to growth in any part of the budget notwithstanding the esteem in which any particular area is held,” Elizabeth Maginnis, the city’s education convener, said.

Edinburgh would try to continue its existing level of provision, Mrs Maginnis said, adding pointedly: “Sadly, this is a comfort I can offer to very few areas of the education service.”

Mrs Maginnis, whose fellow councillors are mostly unenthusiastic about Gaelic education, told The TES Scotland that no children have been turned away from Tollcross, which officials want to cap as a three-teacher unit with no more than 70 pupils.

That prospect was three years away, she stressed. But she conceded the council could be forced to set a “family test” for admission, giving priority to children from Gaelic-speaking homes.

John Macleod, secretary of the Comann nam Parant Gaelic parent organisation in Edinburgh, says capping would introduce selection, damage the viability of the Gaelic nursery at the school and the primary years unit, and have a knock-on effect into secondary.

Some form of Gaelic education is now provided by 16 councils in 142 primaries and 46 secondaries, according to the Leirsinn report. Gaelic-medium provision is available in 52 primaries by 101 teachers to 1,587 children; 25 secondary teachers use the language to teach at least one subject to 180 pupils in 11 schools.

The Scottish Office consultation includes a proposal to make Gaelic-medium teaching statutory where there is “reasonable demand”, defined as requests from the parents of eight or more children. The authorities are opposed.