Frances O'Grady, who will become the trade union organisation's first female general secretary later this year, also accused No 10 of singling out women for some of the deepest public spending cuts, after women's unemployment reached a 25-year high.
"You'd be forgiven for thinking that this was part of a 'back to the kitchen sink' campaign," she said in an interview with the Guardian: "When you look at what's happening, with women being hit hardest by job losses, service cuts, threats to take away employment rights, pay depression and rising bills and lack of childcare... you could be forgiven for thinking there is a plan here."
A preliminary motion at the TUC's annual conference next week warns that increasing unemployment is a "deliberate policy aim of this government". O'Grady said there is "a fair bit of evidence" that lengthening dole queues can be a calculated political move.
"There was certainly a strong view in the 1980s, not just amongst trade unions, but also amongst a number of intellectuals and commentators, that unemployment was being used as a deliberate measure to keep pay down, and to keep people scared. As long as the No 1 worry for people, keeping them up at nights, is whether they're going to have a job in the morning, then they are less likely to resist unfair changes, or unfair treatment, or cuts in real pay at work.
"I think we do legitimately have to ask why the government isn't taking action to create decent employment for young people, when the evidence is that if you don't do that, you really are going to pay a very high price." More than 2.5 million people are unemployed in the UK, a rate of 8%, including a million 16- to 24-year-olds out of work.
This week, the TUC claimed that the number of "underemployed" adults, who want to convertmake their part-time job into a full-time post or wish to work more hours, has risen by 1 million since 2008 to 3.3 million. O'Grady saidalso suggested the increasingly part-time nature of the labour market had made it more difficult to unionise workers. "If you were very cynical," she said, "you might think it was a deliberate strategy."
The biggest "underemployed" group are workers in low-skilled occupations such as farm workers and security guards. This category has grown from 500,000 people seeking full-time work or more shifts to nearly 674,000 people, according to TUC calculations based on official government data. The highest rate of underemployment is among 16 to 24 year-olds, with nearly one in five working people in that age bracket qualifying as underemployed.
The TUC represents 54 trade unions and more than six million workers in the UK.
A Department for Work and Pensions spokesperson said of the TUC's claims: "To suggest [youth unemployment] is a deliberate policy is utterly ridiculous, a ridiculous accusation that is, quite frankly, utterly laughable.
"The government is determined to tackle youth unemployment; the Youth Contract will provide nearly half a million new opportunities for 18 to 24-year-olds and is backed by almost £1bn of funding. We support the creation of jobs be they full time or part-time."