Sarah Lindsell, chief executive of The Brain Tumour Charity, said: “Our thoughts today are first and foremost with Tessa Jowell's family, who have lost someone irreplaceable and loved beyond measure. Her death will leave many lives much poorer.
“It is a shocking reminder of the devastation caused by brain tumours to families around the world and the urgent need to speed up progress towards a cure.
“Tessa Jowell's courage, her spirit and her determination to help others in the face of her own illness – particularly through her extraordinarily brave and powerful speech in the House of Lords - will not be forgotten.
“We will be among those working every day to keep the promise she made, to improve life for everyone diagnosed with a brain tumour.
“Her legacy will live on in countless ways, including The Brain Tumour Adaptive Clinical Trial, which we are launching later this year for patients with the most common type of cancerous brain tumour."