This is the lack of foresight by Supermarket bosses - in driving prices down they drive the suppliers out of business. The supply then dwindles of course.
Yes, it's to do with bird flu. All hens are now indoors, so eggs can't be classed as Free Range - you may notice on the boxes 'Barn Eggs' instead There has been a shortfall in number of eggs. We at Morrisons' were limiting customers to two boxes, Tesco were on three boxes, I think. This is as it was 7 days - been on holiday, back tomorrow. :((
Avian flu means birds that were free range had to be brought into barns, space constraints meant many poultry farmers had to reduce numbers of birds in line with welfare standards. Also any birds in close proximity to wild birds which died from avian flu were culled.
Then fear of shortages caused a degree of over buying, which aggravated the situation. It seems to be quite patchy, Aldi have had plenty ,as had Iceland but strangely enough some stores only had stocks of the higher priced premium brands.
Also
Feed costs have been driven up by grain shortages due in part to the war in Ukraine making production of cheap eggs less viable so supermarkets have lost a lot of their bulk suppliers.
No Breakfast eggs in Wetherspoons recently, although the supermarket next door had plenty