The court is hearing evidence in a case which began with a disagreement over a term-time holiday to Florida. The local council fined Jon Platt, a businessman, £120 for taking his six-year-old daughter out of school for a family trip to Walt Disney World in Orlando. He refused to pay, and Isle of Wight Magistrates said he had no case to answer.

Last May, the High Court ruled in Mr Platt’s favour. But Isle of Wight Council, supported by the Department for Education, took the case to the Supreme Court, arguing that a child’s overall attendance is not relevant.

Flight and holiday prices typically rise by 50 to 100 per cent when schools are out, and increases in air fares tend to be more extreme, with some prices multiplying three or four-fold.

For example, the morning flight on easyJet from Manchester to Geneva on Saturday 18 February — the start of half-term for most schools — costs a family of four over £1,200. A week later, the price for the same seats on the same plane fall to less than £300.

Until 2013, head teachers in England were able to grant up to two weeks a year for family holidays in "special circumstances". But the then-Education Secretary Michael Gove cracked down on parents taking children out of school during term-time. A fixed-penalty fine of £60 is imposed for unauthorised absences; this is doubled if not paid promptly.

The High Court, though, concluded that if a child’s overall attendance is at least 90 per cent, a parent should be able to take them out of school for a holiday.