The Duchess was due to arrive at Hornsey Road Children’s Centre on Monday morning to view its messy play facilities whilst meeting users of its perinatal services.

But the planned visit had to be cancelled because the Duchess, 35, was suffering from severe morning sickness.

Family Action chief executive David Holmes CBE said: “We would like to give our warmest congratulations to the Duke and Duchess of Cambridge

on the wonderful news they are expecting their third child.

“We are honoured The Duchess of Cambridge chose to visit.

“Although she is no longer able to attend we entirely understand why this wasn’t possible,” he added.