Gordon Brown has said Tory plans to slash tax credits are "anti-work, anti-family, anti-children, anti-fairness, anti-women and anti-British" as he urged George Osborne to abandon his policy.
The former Labour Prime Minister, who created the top-up benefit for low-paid workers, called on the Chancellor to do more than tweak the controversial welfare crackdown as pressure mounted on the Tories ahead of details of their U-turn being announced this month.
He singled out "millennials" being worst hit against low wages and the spiralling cost of living, warning young couples were the "new poverty generation".
Mr Brown, in a 45-minute speech marking the Child Poverty Action Group’s 50th anniversary, said if the Osborne plan was "massaged" it was so "fundamentally flawed" it would still lead to a "more divided and polarised" society and inequality rising faster than anywhere in the West.
And he warned child poverty could reach a 50-year high under the Tory plans and called for a “grand coalition” of business and trade unions to oppose them.
He listed seven "facts" about impoverished families as he attempted to bust myths surrounding the Tory plans to find £4 billion of savings through reforming the benefit.
He argued raising the minimum wage to more than £9 an hour and cutting income tax – flagship Government policies - would fail to offset the impact of cutting tax credits.
The former Chancellor noted how even the right-wing had railed against the plan, claiming: "Very soon George Osborne will have doubts about the policies he promoted as George Osborne."
The former MP said there is a Tory "fiction" over poor families that is "at odds with the facts", adding: "The myths have dominated the policy thinking of people who know little about the conditions of the people they represent."
His facts are:
1. The majority of people on welfare in Britain are working families.
"They are not the unemployed, they are not the work-shy, they are not chaotic families."
2. Two-thirds of children in poverty are in working families.
"All the evidence is even if it affected their health they would work longer hours to make ends meet for their children."
3. The biggest group in poverty is the "traditional family", namely a single earner and carer at home.
4. The fastest growing group in poverty are the "millennials", namely couples born after 1980.
"The new poverty generation is young couples in their 20s who are not seeing wage rises. They are seeing rising rents and rising mortgages and are now seeing tax credits cut, and thrust into poverty."
5. Child benefit will equate to less then 10% of bringing up a child by 2020.
"The myth is benefits are so great they are somehow abusing the system, when child benefit cannot meet a fraction of the cost of bringing up a child."
6. Low pay is the biggest cause of poverty in this country.
"The Living Wage has to go side-by-side with decent child benefits and child tax credits."
7. Child tax credits and child benefits are the most cost-effective way to take children out of poverty.
The Chancellor has said he will unveil a new-look policy at his Autumn Statement this month after the House of Lords voted to block his plans.
The MP-turned-anti-poverty campaigner went on: "The world is not divided between the contributors and the claimants, the scroungers and the strivers. At various points of our lives we will rely on the welfare state."
He concluded: "When it comes to these reforms, they are anti-work, anti-family, anti-children, anti-fairness, anti-women and, in my view, anti-British."
TAX CREDITS: THE IMPACT
Tax credits are welfare payments to families raising children and working people on low incomes.
More than three million families would lose an average of £1,300 a year from April under the previously announced plans.
The cuts will deliver £4.4bn of the Chancellor’s planned welfare cuts by reducing the earnings level at which tax credits start to be withdrawn from £6,420 to £3,850.
The Government says eight out of 10 would be "better off" overall from a package which also includes increases in the minimum wage for over-25s, rises in the income tax threshold and extended free childcare.