A welfare fund set up by a trade union to help members pay heating and other bills paid out a record £750,000 last year.
A "massive" increase was recorded in the number of applications for grants, with calls to help pay heating bills rising by almost 400%, Unison said.
The fund paid out 11% more than in 2011, while Unison officials increasingly reported that public sector workers are being forced to rely on food banks to feed their families.
Unison general secretary Dave Prentis said it is not just the unemployed who struggle to pay bills and buy essentials such as food.
"The number of working people in poverty is on the rise in Tory Britain. The coalition Government is hitting working families and it is hitting them hard.
"Our welfare fund used to pay for well-being breaks but the recession means that holidays are a thing of the past for low-paid families. What people need now is help with the basics of life such as food and fuel.
"Parents say they dread the bill for school uniforms when the new school year begins. In some cases the cost runs to hundreds of pounds and they just can't afford it. It is heartbreaking to read their applications where they spell out the struggles they face and how difficult things have become.
"The stress of the struggle to make ends meet is making many sick. They've lost working tax credits and it has pushed them over the edge. Some can't even afford the weekly shop and have to rely on their family for help with groceries.
"The Government needs to get real about the depth of the crisis. The Government urgently needs a plan for growth and jobs in 2013, not simply to be ploughing ahead regardless with an economic plan that is not working."
The union is urging the coalition to end the public sector pay freeze which has hit millions of workers for two years and local government workers for three.