Liberal Democrat Danny Alexander has accused the Conservatives of being bent on "slashing support for families" while the two parties were in coalition.
Alexander said £8 billion of proposed welfare cuts that the Lib Dems blocked included limiting Child Benefit and Child Tax Credit to two children at a cost of £3,500 for a family of three.
The Tories said they did not recognise the figures cited and called the claim "desperate stuff".
Labour leader Ed Miliband has responded to the Liberal Democrats leak that claims the Conservative party planned £8 billion of welfare cuts.
A Conservative Party spokesman denied Alexander's claims.
"This set of policies was never proposed or supported by the Prime Minister and Chancellor and would never be proposed or supported by the PM and Chancellor," a spokesman said.
The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.