Tessa Jowell's battle to improve care for cancer patients in her final days as she was dying from a brain tumour is to be shown on television.
Behind the scenes footage recorded in April and early May with the former culture secretary, a driving force behind the 2012 Olympics, will be included in a Panorama episode to be broadcast on Monday.
Baroness Jowell, who served as a minister under Tony Blair, died at the age of 70 on May 12 after being diagnosed with the brain cancer glioblastoma multiforme (GBM) a year previously.
Panorama was given behind the scenes access to the peer's family as she used the House of Lords as a platform to discuss her condition and call for patients to have better access to experimental treatment.
The last filming took place a week before Lady Jowell passed away, the BBC said.
Her daughter Jess Mills told the programme: "The only time I've seen mum cry since she got ill, she was sat in the waiting room and had what she described as the absolutely heartbreaking realisation that those who had that privilege of access or income may well live longer because of that and those that didn't may well die much sooner because of it.
"And in her words, that is just the most despicable example of inequality. In those moments, her mission was really identified."
Following Ms Jowell's death the Government invested a further £20 million to the Tessa Jowell Brain Cancer Research Mission, doubling its funding to £40 million over the next five years.
On Tuesday it was revealed trials of a vaccine for GBM could add years to sufferers' lives.
Early findings from an 11-year trial involving more than 300 sufferers worldwide show those given the vaccine "are living longer than expected", according to a paper published in the Journal of Translational Medicine.
Among those to feature in the programme will be cancer specialists and patients with the same form of brain tumour.
Tessa Jowell: Her Last Campaign will be broadcast at 7.30pm on June 4 on BBC One.
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