“It could mean in practice that the Foreign Office focuses on political stuff and away from some of the areas we have been known for, such as health and climate stuff,” the source said.

A source close to the Foreign Secretary, who is also the Government’s minister for women and equalities, confirmed that she intended to prioritise development spending on women and girls but denied that climate change and global health would be defunded, pointing to plans for the budget to be spent on sustainable infrastructure in poor countries.

The concerns from officials came as more than 200 British NGOs wrote to Ms Truss to urge her to continue spending on climate and health projects and to restore the UK’s previous aid spending commitment of 0.7 per cent of gross national income (GNI).

‘Short-sighted’

The letter, coordinated by Bond, an international development network, said: “It would be short-sighted to drop critical issues like global health, climate change and conflict prevention from the forthcoming International Development Strategy. It would also cost lives.

“These are areas where the UK has a strong track record of impact and significant expertise and this move will undermine the UK’s ability to play our part globally in tackling urgent challenges, increasing security, and eradicating poverty.

“Supporting countries in times of crisis is critically important, but so too is investing in the development assistance that prevents these crises.”

An FCDO spokesperson said: “International development remains a core priority for the FCDO. We will publish a new International Development Strategy this Spring.

“This will set out how we deliver our climate change and health commitments, as well as restoring funding for women and girls and humanitarian work this year.”