In a letter, the parties called on the PM to fund the programme, subject to appropriate scientific proposals, independent peer review and governance. 

The joint letter states: ‘Cancer is not party-political. Neither is the research needed to defeat it.'

Invasive lobular breast cancer is the second most common form of breast cancer, with around 22 women diagnosed every day in the UK. Yet there remains no treatment specifically designed for its distinct biology. 

The Lobular Moon Shot Project has now secured the support of 469 MPs, according to the campaign's latest count.

The campaign is seeking funding for a dedicated discovery-science research programme designed to improve understanding of the disease and ultimately improve diagnosis, treatment and outcomes.

A Government spokesperson said: ‘We are all united in supporting women and families impacted by lobular breast cancer. This form of cancer sadly goes undetected in too many women, and we need both high-quality, ambitious research, and improved diagnosis and treatment, in order to transform outcomes for patients.

‘Through our National Cancer Plan, we are working to bring the latest scientific breakthroughs into the NHS faster so that patients benefit from earlier diagnosis, more effective treatments, and better quality of life, and we will continue to work with stakeholders across the political spectrum and beyond to drive forward that plan.'