They say 22,840 families across Milton Keynes face the government's Universal Credit cut.
According to data, 21% of hard-pressed families in Milton Keynes North, and 21% in Milton Keynes South, face being left worse off when the government end the uplift to Universal Credit next month.
New data from the Joseph Rowntree Foundation exposes the true nature of how badly some areas will be hit by the £20 Universal Credit cut, which is opposed by Milton Keynes Liberal Democrats.
The Joseph Rowntree Foundation estimate that the Universal Credit cut alone could force 500,000 people, almost half of them children, into poverty.
Their breakdown shows that some 11,410 families in Milton Keynes North will be harmed by the governments uplift cut, with 39% of families with children in the constituency being affected adversely.
In Milton Keynes South, it is around 11,430 families, with 37% of families in the area being adversely affected.
Responding to the data, Councillor Robin Bradburn, Liberal Democrat Group Leader on Milton Keynes Council said: "Milton Keynes has had to pull itself through this pandemic, while dealing with this incompetent heartless Conservative government, this cut will do untold damage to so many of our local families.
"There is no question that Government has to reverse this needless cut and support normal working people here. Milton Keynes Liberal Democrats are calling for the Universal Credit uplift to be made permanent."
Liberal Democrat Work and Pensions Spokesperson Wendy Chamberlain MP added: “Just as we begin to hope that Covid is being tamed in the UK, the Government is ripping support from millions of families across the country. We cannot have a full recovery if families are struggling to make ends meet.
“The Prime Minister's claim that he wants people to live by their own 'efforts' rather than 'welfare' shows how out of touch he really is. With almost half of those receiving Universal Credit already in work and with many having young families, this cut will leave parents and their children behind despite their efforts."