Champion, who chairs the international development committee, said military officials believe the “best line of prevention and first defence is our development money”, as she warned the cuts could have “massive consequences”.
She said these included people “coming to our shores” to seek sanctuary and opportunities that will have been reduced in their own countries.
Liberal Democrat international spokesperson Monica Harding described the government’s approach as “strategically illiterate” and warned Russia or China could fill the vacuum left by the UK.
She said: “By cutting aid and development [Cooper] weakens our security and therefore needs more defence spend down the line.”
Asked for assurances that the UK would continue to support efforts to eradicate Polio, Cooper said: “We are not continuing the direct funding around Polio, that is a difficult decision.
“But what we are doing is insisting that Polio is covered as part of the Gavi funding.”
Bond CEO Romilly Greenhill said: “Africa and the Middle East, both home to some of the world’s least-developed countries, will be forced to pay the highest price because of the reduced budget.”
Adrian Lovett, UK executive director of the ONE Campaign, said: “Slashing bilateral aid to Africa, where need is greatest, will have a devastating impact.
“These choices will leave millions without access to basic healthcare, education and urgent humanitarian support, and risk a resurgence of deadly diseases we’ve spent decades trying to fight.”