Long-term damage will be done to the UK economy unless the Government changes course on economic policy, the shadow chancellor will warn.
The coalition's economic plan has failed, leaving businesses and families "crying out" for an alternative, Ed Balls will tell the Trades Union Congress in Brighton.
"Britain is just one of two G20 countries in recession: the longest double-dip recession since the Second World War. Living standards face the biggest squeeze since the 1920s, with prices rising faster than wages. Unemployment is high, with long-term youth unemployment rising month by month," he will say.
"And the costs of this economic failure are rising, with borrowing up by a quarter so far this year. But it does not have to be this way; because we now risk a lost decade of slow growth and high unemployment which will do long-term damage.
"Over 33,000 companies already gone bust since the general election. Investment plans cancelled, or diverted overseas. New ideas and new ventures being promoted in other countries.
"Our economy weaker and capacity lost and, above all, long-term youth unemployment becoming entrenched, damaging young lives and racking up costs which we will all have to pay.
"Not short-term pain for long-term gain, but short-term pain causing long-term damage as we pay a long-term price for this Government's economic failure. That is why we need action now, a change of course and a plan for jobs and growth: investing in infrastructure, building new homes and getting young people back to work."
Labour will look at measures to tackle bogus self-employment which can be used to undermine employment rights and avoid tax, Mr Balls will say.
"There is a careful balance to be struck. I do not want in any way to undermine genuine self-employment, but nor should contractual arrangements be distorted and misrepresented to avoid tax and undermine terms and conditions. It's not fair to taxpayers and it's not fair to your members either."
Mr Balls will face questions from delegates after his speech, with activists planning to tackle him on Labour's welfare plans and on his controversial support for public sector pay restraint.