SEDBERGH School headmaster Andrew Fleck has robustly defended its merger with neighbouring Casterton, laying bare for the first time the reasons he claims the move was necessary.

Mr Fleck showed The Westmorland Gazette accounts which revealed Casterton School went from making a surplus of £400,000 between September 2010 and August 2011, to a loss of £535,000 by August 2012 - a ‘negative movement’ of nearly £1 million.

Mr Fleck said Casterton’s governors felt the 190-year-old boarding school, near Kirkby Lonsdale, had become ‘economically unviable’.

“It’s the unfortunate consequence of the recession and people choosing not to send their daughters to single-sex schools,” explained Mr Fleck.

Figures show the number of boarding pupils in the all-girl senior school has fallen by a quarter since 2011, senior school day pupils are down 19 per cent and the junior school head count has dropped 36 per cent.

This has led to a 14 per cent drop in income, a figure it was feared would fall a further 15 per cent by August.

The merger, which will see Casterton girls move to Sedbergh and Sedbergh Junior School relocate to a new preparatory school at Casterton, was met with anger when announced in February, when Casterton parents demanded a u-turn and said they should have been consulted.

Speaking as the accounts were due to be signed off this week, Mr Fleck said consultation could have ‘destabilised’ the school and potentially led to its closure.

“Given the financial situation, there was an urgency to merge the schools,” he explained.

“If parents had been told the school was considering merging with Sedbergh because of the finances and parents had left, the cashflow might not have been secure to enable the school to continue this academic year.”

At least ten current Casterton pupils have withdrawn from the school, or plan to, ahead of September’s switchover.

The merger, which a group of campaigners is trying to overturn at a July court hearing, has resulted in 49 jobs being axed.

Forty-seven have been voluntary redundancies but two teachers have been made redundant through compulsory losses.

Keen to dispel rumours that mostly Sedbergh School staff had been retained, Mr Fleck said: “Of the new teaching staff in the senior school, two thirds of the academic department will have Casterton teachers. Overall, 24 per cent of the teachers will be from Casterton.

“When you look at the relative size of the school, if all the Casterton teachers had a job, that would have been 50 per cent of all staff.”

He said the staff process had been fair, adding: “I’m very excited about the calibre of staff for the future.”

Sedbergh headmaster since 2010, Mr Fleck accepted there was a ‘high degree of emotion’ over the merger and said he was ‘sympathetic’ to parents’ views.

But he insisted the move was the right one and said the planned legal challenge by opposition group Casterton Parents Limited to unwind the merger would be too late, as teachers and parents will have already made new arrangements.

“We have not been told who Casterton Parents Limited are, despite asking. I absolutely believe that, legally, it’s irreversible, and I am even more certain that practically it’s irreversible.

“It’s really important that pupils, families and staff focus on the future.

“I’m enormously excited that this part of Cumbria now has the opportunity to have truly one of the greatest schools in the country.”

A Casterton Parents Limited spokeswoman said the group had ‘no recollection’ of being approached by Mr Fleck but that it would be ‘delighted’ to meet with him.

She added that legal action would proceed as members felt ‘wrongs’ had taken place in the merger decision process.

Current Casterton School headmistress Maxine Lucas said: “The governors, as trustees of the school, believe that the merger with Sedbergh offers the best option for Casterton in the current economic climate.”