The world’s best-selling toy firm said it had failed to predict an 18 per cent boost in sales earlier this year which had put “strain” on its manufacturers.
The Danish company apologised and insisted it would try to ensure it was not “disappointing children”.
Experts said that Lego’s popularity following the Lego Movie and its Star Wars range meant demand was exceeding supply.
Lego spokesman Roar Trangbaek said retailers which had already made orders will have their products delivered.
He added that “select countries” could be affected but refused to comment on whether that included the UK or which toys could be hit.