The move, announced by finance minister Rishi Sunak as part of an annual review of government spending, will be popular among some voters and media who argue that COVID and the resulting economic crisis mean Britain should spend less on aid.

"During a domestic fiscal emergency, when we need to prioritise our limited resources on jobs and public services, sticking rigidly to spending 0.7% of our national income on overseas aid is difficult to justify," Sunak said in a speech to parliament, pointing to record high peacetime borrowing levels.

He said aid spending would rise to 0.7% again when fiscal conditions allowed, but did not set a target date.

The government minister for sustainable development, Liz Sugg, resigned over the decision, saying it diminished Britain's global influence.

Several senior members of the ruling Conservative Party, including former foreign minister Jeremy Hunt, also criticised the decision, hinting at a possible rebellion in parliament.

"To cut our aid budget by a third in a year when millions more will fall into extreme poverty will make not just them poorer, but us poorer in the eyes of the world," Hunt said.

The announcement was also criticised by Archbishop of Canterbury Justin Welby, the head of the Anglican Communion, who called it shameful and wrong.

Development and environment charities said the move was short-sighted.

"Cutting the aid budget during a global pandemic is like closing fire stations during a heatwave," said Patrick Watt of Christian Aid.

Oxfam said the decision would diminish British influence and leadership at a time when both were badly needed.

(Reporting by Estelle Shirbon, David Milliken and William James; editing by Stephen Addison)

By Estelle Shirbon