Liberal Democrat ex-cabinet minister Michael Moore is introducing a backbench bill to make it a legal requirement that at least 0.7% of Britain's GDP is devoted to helping poor countries, in line with a United Nations target.
The coalition government agreed to the amount last year, but the promised legislation has so-far failed to materialise.
The 0.7% pledge, in line with the UN target, has previously had the backing of all three major parties, but this is the first time it will be enshrined in UK law.
More top news
Storm Imogen - when and where we will see the strongest winds? ITV Weather's Manali Lukha gives the breakdown.
Kate Middleton attended a special service to celebrate the landmark occasion in her first engagement as Honorary Air Commandant
The ISIS execution gang fronted by 'Jihadi John' had two British extremists who learned radical Islam together in London, ITV News reveals.