The pay of public sector workers will have been cut by thousands of pounds over the lifetime of the coalition Government because of wage freezes, VAT hikes and changes to benefits and tax credit, according to a new study.
Unison said the lowest paid workers have been hardest hit, estimating that some healthcare assistants will have lost 50% of their income by 2015.
Families have suffered "multiple hits" since 2010, which Unison said was contributing heavily to the lack of economic growth.
The report, published at Unison's national conference in Liverpool, said nurses, paramedics, teaching assistants, social workers and care assistants are among those who will be worse off by thousands of pounds.
Unison general secretary Dave Prentis said: "Far from the Government's strivers and shirkers rhetoric, hardworking families are coming under heavy fire from the coalition. These families did not cause the crisis, but over the course of this parliament they will pay a huge price for it.
"The damaging effect of this unprecedented squeeze cannot be underestimated. Working people are turning to food banks, parents going without meals, and holidays are a distant memory.
"We are urging the Government to end the squeeze on pay, and to look again at the tax and benefit changes that are hitting those on low and middle incomes so hard.
"By taking money out of people's pockets, this Government has hit hard our chances of recovery. No wonder our economy is stubbornly stagnant - people have no money to spend.
"Instead of this ruthless strategy, the Government could take serious action on tax havens and tax avoidance, put in place a Robin Hood Tax or reverse the millionaires' tax cut which has cost our country more than £2 billion this year alone."