'There won't be any left at all by the end of the season,' said Joanne Atkins of the Hat Shop in Covent Garden, London. It has already run out of Latin American imports. Some 60,000 Panamas were brought to Britain by the largest importer this summer (it was fewer than 4,000 in 1985) and imitations are made here.
'They are popular with everyone,' Ms Atkins said. 'I sold three today, one to a man of 24 and one to a young lady, as well as one to a man of 70.' The Genuine Panama Hat Company, a mail-order firm, put this down to 'sun protection, and nostalgia'.
The Yellow Pages advert in which a cricket umpire picks up his new Panama in Cheltenham on his way to the Test has also played a part.
One Panama devotee of 40 years' standing is delighted to find himself suddenly so fashionable: 'I wear mine all summer whenever I'm outdoors. I also sometimes wear it indoors when I am watching Wimbledon on the television, to get that summery sporty feel.'
Panama hats in fact come from Ecuador, where fine straw is hand-woven into the distinctive close-meshed sombrero de paja toquilla, as it is known locally. 'But,' as the Genuine Panama Hat Company spokesman pointed out, 'if you ask for an Ecuador hat no one will know what you're talking about.'
The genuine article is so strong and flexible that it can be folded into a pocket or storage tube without losing its shape.
Panamas have existed since the 16th century, but became popular further afield when they were adopted by the US Army in the Caribbean at the turn of the century. Edward VII made them fashionable in Britain when he wore one to Goodwood.
Today's Panama ranges from the ultimate pounds 500 hat in finest Montecristi Ecuadorean straw, from London hatters Locks of St James's, through folding versions from the Hat Shop ( pounds 75) to the Hat Shop's day-trip version that, at pounds 4.95, has never been near Latin America.
Controversy rages over the exact shape for the chic-est Panama. Johnnie Boden, a mail-order seller, makes a point of wider brims. 'Small brims look awful,' he said.