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
The world's top scientists have called for a ban on autonomous weapons and "killer robots" that can attack targets without human control.
Growth figures published today are set to show the economy bouncing back after a weak start to the year.
A stagnating jobs market has created a blockage in the career progression and earning potential for many younger works, a new report says.