Joan Olivier, the doughty Scot who runs the Lady Margaret School in west London, is on the warpath.
"If the BBC call it an entrance exam, I'll sue it within an inch of its life," she says. "It's an assessment test."
The BBC did call it an entrance exam. Last night on Just One Chance, it accused the school, called the fastest improving comprehensive in the country, of operating an admissions policy that gives it far more than its fair share of bright, middle-class girls.
Critics say this fully explains the school's outstanding academic success. In 1996, 90 per cent of its pupils got at least five higher-grade passes at GCSE, putting it seventh in the national league for state schools.
But the reason for press interest in the school this week was not selection but politics: the news that Tony and Cherie Blair are considering the school (among others) for their daughter Kathryn. Mrs Blair has, it seems, been spotted at a parents' open day. Have the Blairs applied for a place? "I couldn't possibly tell you - that's highly confidential," says Mrs Olivier. Having braved much adverse comment when they chose a grant-maintained Catholic school, also in Fulham, for their sons Euan and Nicholas, are the Blairs about to attract equal criticism over their choice of school for their daughter?
Lady Margaret is a 500-pupil Church of England School on Parsons Green, in the London borough of Hammersmith and Fulham. As a voluntary-aided school, it runs its own admissions policy. Half of the 90 places a year are reserved for active Anglicans; the other half are open to both Christians and non-Christians. (It is not clear into which category Kathryn Blair would fall, with a devoutly C of E father and a devoutly Roman Catholic mother.) Under the admissions procedure, the school runs an assessment test in November "to achieve a genuinely comprehensive intake", followed by interviews of parents with their daughters in January to see if they share the school's ethos.
On the basis of tests similar to those used under the old Inner London Education Authority, the school expects to admit each year about 25 girls of above average ability, 49 of average and 16 of below average ability.
Last night, Just One Chance took issue with this claim. The programme cited local authority figures showing that only one of last year's GCSE candidates from the school was of below average ability and only eight were rated average. The overwhelming majority - 51 girls - were in the top ability group.
Lady Margaret School certainly attracts a lot of bright applicants, lured by the excellent results. Last year, 490 girls were chasing 90 places, with competition fiercest for the 45 non-foundation places. The school does select a fair range of ability from those who apply, a borough spokesman conceded to The TES this week.
Iain Mills, MP for Hammersmith and Fulham and former council leader, and David Williams, who chairs the borough's education committee, complain that they would like to see more local children admitted to the school. But, as Mrs Olivier points out, Lady Margaret is not a neighbourhood school. "It's a church school," she says. "Children come from all over south London and some parts of north London."
She said her girls were amazed by the picture of the school given in the press on the basis of the television report. "They didn't realise they were so rich and so brainy". She said the school had 87 children with special educational needs, of whom three had statements.
"They're certainly not all from suburban, middle-class homes," she told The TES.
"One change I made when I arrived was to take "parent's occupation" off the application form - we certainly don't want a duke's daughter."
The school may not want a duke's daughter but does it want a Prime Minister's?