Royal Family: William and Kate looked relaxed in first public outing since Harry's book release

William and Kate looked relaxed as they arrived to officially open the new Royal Liverpool University Hospital in the home city of The Beatles.

Harry's controversial autobiography, Spare, has become the fastest selling non-fiction book in history, according to publisher Penguin Random House, which reported more than 1.4 million copies were sold on Tuesday, the first day it went on sale.

The book includes claims the Prince of Wales physically attacked Harry and teased him about his panic attacks, and that the King put his own interests above Harry's and was jealous of the Duchess of Sussex and the Princess of Wales.

Reports of a fractious friendship between Meghan and Kate were confirmed in Spare, with Harry recounting how the princess, pregnant at the time with Prince Louis, said she was owed an apology from his wife who had previously commented Kate was suffering from "baby brain" due to her "hormones".

He shed further light on the row over Princess Charlotte's bridesmaid dress claiming, contrary to reports at the time, Kate was not in tears but the incident had left Meghan "sobbing on the floor".

During a series of interviews to promote Spare, Harry defended himself against strong criticism, following his revelation in the book he killed 25 Taliban members during the Afghanistan war.

He denied boasting about the killings, when interviewed by Stephen Colbert on CBS's The Late Show, and claimed members of his family are in an active campaign to "undermine" his autobiography.

The King also carried his first official engagement since the publication of his son's book, visiting the community of Aboyne, close to the late Queen's Balmoral estate in Aberdeenshire, to tour the Aboyne and Mid Deeside Community Shed and meet local hardship support groups.

A YouGov poll has found the popularity of Harry has fallen since his book was published with 68% of 1,691 adults, polled on Tuesday and Wednesday, having a negative opinion about him while 24% thought positively.

The online research data group said the figures meant the duke had his lowest ever net favourability rating of minus 44, down from minus 38 last week, which had been his previous record low.

Meanwhile Prince Harry’s memoir is expected to be the biggest selling non fiction book published in Ireland in the last 20 years.

The Duke of Sussex’s controversial memoir looks set to break records in Ireland, after it sold more than 10,000 copies on its first day of publication.

Penguin Random House, who published the autobiography Spare on Tuesday, said it continues to sell strongly in all formats across Ireland.

While official figures will not be published until Tuesday, it looks set to beat the current record-holder, Paul O’Connell’s The Battle, which sold 17,800 in its first week during Christmas 2016.

“Sensational sales of over 10,000 copies of Spare by Prince Harry in Ireland yesterday,” Michael McLoughlin, publisher of Penguin Random House Ireland, tweeted.

“It’s going to be close, but it looks like the first week’s sales may beat the best single-week sales of every non fiction book published in Ireland over the past 20 years!”

It’s understood sales of the tell-all memoir continues to build across Ireland, but official figures won’t be released until next week.

It is expected that Prince Harry’s book will sell more than ‘The Battle’ as the former Irish rugby player’s book was released ahead of Christmas, during the busy gifting period.

Penguin Random House confirmed on Thursday that the English language edition of the memoir sold more than 1.4 million copies on its first day of publication.

The publishing company reported their largest ever first-day sales total for any non fiction book.