There are fears unemployment could top three million by the end of the year
Britain is on the road towards recovery but things remain fragile, Prime Minister Gordon Brown will tell the TUC's annual congress this week.
He will warn of tough choices in public spending but call on the unions to support the government's approach.
TUC general Secretary Brendan Barber said there would not be a "real recovery" until unemployment came down, but added this seemed a "long way off".
On Friday, Mr Brown held talks with union bosses at his Chequers residence.
The TUC's congress, which starts in Liverpool on Monday, will be the last one before the next general election and it comes at a time of strained relations between the unions and the government.
But Mr Brown will deliver an upbeat message to delegates when he speaks on Tuesday, declaring "we are on the road to recovery", though he will say this will not be automatic and the recovery will need to be nurtured.
'Stimulate the economy'
The prime minister will say that he will protect front-line jobs and urge TUC members not to disrupt the government's efforts with industrial action.
Mr Brown will also say: "People's livelihoods and homes and savings are still hanging in the balance, and so today I say to you: don't put the recovery at risk.
"We have to make tough choices in public spending and we will need the support of the labour movement in protecting the front line first."
Mr Barber told BBC One's Politics Show: "Our biggest problems are the recession and unemployment. That's what the government needs to be focusing on.
"A time will come when we need to get the deficit down, but that's not the stage that we are at."
Mr Barber urged the government not to cut public spending, saying that this could hinder economic growth.
He added: "I think we are beginning to see some first sense of recovery and I think we may begin to see some data that, by the end of the year, economic growth is on a positive path again.
"I don't think it's a real recovery until we see unemployment come down and we are a long way from that."
Government hints at a much tighter rein on public spending have reinforced the unions' concerns about jobs.
The prime minister will tell the conference that public sector jobs would be at greater risk under the Conservatives.
"Don't risk it with the Tories whose obsessive anti-state ideology means they can't see a role for government in either recession or recovery," he will say.
"Our opponents have one approach to reducing the deficit: slashing jobs and abandoning national pay bargaining.
"We have another - taking tough choices and empowering those who deliver services to innovate and secure greater value for money."
On Friday, the prime minister met 15 trade union leaders for three hours, with a spokesman saying the talks had been "wide-ranging" and "constructive".
The government says it wants to halve the budget deficit - expected to be £175bn this year - over the next four years but unions say this must not involve mass redundancies.
Despite recent signs of a tentative economic recovery, there are fears that the number of people out of work could top the three million mark by the end of the year.
In an interview with the Independent on Sunday, Derek Simpson, leader of the Unite union, says that, if Mr Brown stops being Labour leader, Energy Secretary Ed Miliband should replace him.
Mr Simpson describes him as "quite good, if I had to pick a leader for the future".
But Mr Miliband told BBC One's Andrew Marr Show that Mr Brown was the "right leader" and that he was "not going to stand aside".
He also said: "Derek's on a one-man mission to destroy my career, at many different levels."
Home Secretary Alan Johnson told BBC One's Politics Show: "I believe we have the absolute best leader of our party. There is no-one else who can do the job as well as Gordon Brown has done.
"We cannot as a team stand in the middle of the pitch deciding who our captain should be while the other team runs rings around us."