‘We’re thrilled’ - Duke of Cambridge speaks of royal baby joy

William said the Duchess of Cambridge had experienced a “tricky few days” with very acute morning sickness, but they are thrilled at her pregnancy.

Speaking during a visit to Oxford University’s new £21 million China Centre, the Duke said: “She’s feeling OK, thanks. It’s been a tricky few days - week or so - but obviously we’re basically thrilled, it’s great news, and early days. We’re hoping things settle down and she feels a bit better.”

During her pregnancy with one-year-old Prince George, Kate was treated in hospital for hyperemesis gravidarum. She was forced to pull out of yesterday visit due to the condition but is being treated by doctors at home.

Although a due date has not been announced, it is understood that the pregnancy has not passed the 12-week stage - a similar position to when Kate was struck by the illness when in the early stages of her first pregnancy.

The couple said they were “very pleased” to reveal Prince George will have a new brother or sister. The Queen and members of both William and Kate’s families are “delighted” at the news, Kensington Palace said.

Political leaders and the Archbishop of Canterbury offered their congratulations yesterday, with The Most Rev Justin Welby calling for divine intervention to help ease the Duchesses’s acute morning sickness suffered by the Duchess.

He said: “Wonderful news that the Duke & Duchess of Cambridge are expecting second child. Praying for the family, and that morning sickness subsides.”

Prime Minister David Cameron said he was “delighted” by the news, a view echoed by fellow Westminster party leaders Ed Miliband and Nick Clegg.

Father-of-three Mr Clegg advised the royal couple to “stock up on as much sleep as you can” before the new arrival.

Labour leader Ed Miliband said: “Fantastic to hear that Prince George will soon be a big brother!”

The couple’s second child will become fourth in line to the throne, shifting Prince Harry further down the line of succession.

Speaking as he visited competitors training for the inaugural Invictus Games yesterday, Harry said it was “very exciting news”.

The announcement of Kate’s second pregnancy comes just days before the start of the games for wounded and injured soldiers, which have been championed by Harry and backed by his brother and sister-in-law, who was expected to attend to opening ceremony tomorrow.

After watching final training sessions, Harry said Kate was “pretty poorly” but “doing the best she can”.

Asked whether he could give the new baby any advice on being a younger sibling, he said: “I think George will be over the moon. I think he will be thrilled having another small younger brother or sister.”

And when it was put to Harry that the new addition to the royal family would further reduce his own chances of being King, he laughed and replied: “Great!”

Earlier, Mike Tindall, the Yorkshire-born husband of Zara Phillips, hinted that he would get the new prince or princess a Leeds United shirt.

The announcement will throw into doubt whether the Duchess will be able to attend her first solo overseas tour, set to take place in Malta later this month.

A Kensington Palace spokesman said her attendance at future events would be decided on a “case by case” basis.

She is scheduled to attend the opening ceremony of the Invictus Games in London tomorrow evening, along with William, Harry and the Prince of Wales and Duchess of Cornwall.

Rumours about a second child have been rife since April, when William told a woman who presented him with a lace shawl: “You might have to make another one soon.”

Bookmakers have already been kept busy by royal enthusiasts waging money on all aspects of the birth.

Although the due date has not been released, William Hill, who took over half a million pounds on Prince George’s birth, have odds of 16/1 that the baby will be born on April 21 - the Queen’s birthday.

A multiple birth could mean big money with Paddy Power offering odds of 33/1 for twins and 250/1 for triplets.

Front-runners for the baby’s name include Elizabeth, Henry and Victoria at 10/1 with Paddy Power, and Alexander and James at 9/1 with William Hill.