Rishi Sunak led messages of support for the Princess of Wales from across the political spectrum after she announced she was undergoing treatment for cancer.

The Prime Minister praised Kate's "tremendous bravery" after she revealed that she had been diagnosed with the disease and was in the early stages of chemotherapy following mounting speculation about her health.

He said the royal has "the love and support of the whole country" and called for her to be given privacy as she continues treatment, criticising the "intense scrutiny" she has been subjected to in recent weeks.

People outside Buckingham Palace in London, after the Princess of Wales revealed she is undergoing chemotherapy treatment for cancer. Photo: Yui Mok/PA Wire

Mr Sunak said: "My thoughts are with the Princess of Wales, Prince of Wales, the royal family and in particular her three children at this difficult time. The Princess of Wales has the love and support of the whole country as she continues her recovery.

"She has shown tremendous bravery with her statement today. In recent weeks she has been subjected to intense scrutiny and has been unfairly treated by certain sections of the media around the world and on social media.

"When it comes to matters of health, like everyone else, she must be afforded the privacy to focus on her treatment and be with her loving family.

"I know I speak for the whole country in wishing her a full and speedy recovery and look forward to seeing her back in action when she's ready."

Home Secretary James Cleverly said: "Hoping that she has a speedy and complete recovery and privacy and calm while she does."

Chancellor Jeremy Hunt said: "All my thoughts and prayers are with our courageous Princess of Wales.

"Such incredibly tough news to break to three young children - let's give them the space and privacy they need to protect their family and focus on getting better."

Labour leader Sir Keir Starmer said the princess has "the love and support of not just her whole family, but the whole nation too" during this "distressing time".

The Labour leader also condemned "lurid speculation" that has surrounded her condition saying: "Any cancer diagnosis is shocking. But I can only imagine the added stress of receiving that news amid the lurid speculation we've seen in recent weeks.

"Their Royal Highnesses are entitled to privacy and, like any parents, will have waited to choose the right moment to tell their children.

"I am heartened by The Princess of Wales' optimistic tone and her message of faith and hope. Her Royal Highness will be in our thoughts and prayers as she progresses through her treatment with the love and support of not just her whole family, but the whole nation too."

First Minister Humza Yousaf said: "I'm deeply saddened to hear the news about the Princess of Wales/Duchess of Rothesay. I am praying for her swift recovery.

"It must be an incredibly difficult time for the whole family. Royalty or otherwise, she has a right to privacy, which I hope will be respected."

Liberal Democrat leader Sir Ed Davey said: "What sad news. My thoughts and prayers are with the Princess of Wales tonight.

"Liberal Democrats join the whole country in wishing her a speedy recovery and hope the Royal Family will be given space and privacy at this difficult time."

Commons Speaker Sir Lindsay Hoyle sent well wishes on behalf of the House and said Kate's candour would make a difference to others facing their own battle against cancer.

He said: "The Princess of Wales has been incredibly brave in revealing her cancer diagnosis and I am sure her candour will make such a difference to all those facing this dreadful disease.

"On behalf of the House of Commons, I would like to send my best wishes to Catherine and her family and hope she will be back to full health very soon."

Douglas Ross, leader of the Scottish Conservatives, also expressed his support for the princess.

In a statement sent via the party’s press office, he said: “I join people across the world in sending my best wishes to Her Royal Highness for a full and speedy recovery, following her dignified and courageous statement.

“So many people will be able to relate to this situation because of their own experience with cancer, or that of a loved one.

“My thoughts are with the Duchess of Rothesay and the entire Royal Family as she begins her treatment.”

Anas Sarwar, leader of Scottish Labour, said Kate was “courageous” for posting the video statement.

On X, he wrote: “This is a courageous video from the Duchess of Rothesay.

“My thoughts are with her, her husband and children, and all of the Royal Family.

“We wish her a full and speedy recovery.”

Alex-Cole Hamilton, leader of the Scottish Liberal Democrats, wrote on X: “On behalf of the (Scottish Liberal Democrats) I’d like to wish the Princess of Wales all the very best on her journey to recovery following her diagnosis.

A spokesperson for the Scottish Green Party wished the princess a quick recovery.

They said: “As with all those suffering from cancer, we would wish Catherine a speedy recovery.”

SNP Westminster leader Stephen Flynn said: "We all know the suffering and distress that a cancer diagnosis brings to individuals, their families and friends.

"I wish Kate well in her battle, and have no doubt that her words will be of comfort and support to others facing their own."

Shadow foreign secretary David Lammy said: "Incredibly moved by the bravery of Her Royal Highness.

"At this extremely difficult time, her message to others affected by cancer will mean so much to so many.

"Wishing The Princess of Wales, and the whole Royal Family, the very best in recovery.

"May all respect their privacy."

Politicians wish Kate well after cancer treatment announcement