He and Chancellor Rachel Reeves have been warning that next month's Budget will be "painful", sparking fears of spending cuts.
But the Prime Minister said he would give people hope for a "changed Britain" after gloomy tidings of tough choices to come.
And the former head of the Crown Prosecution Service vowed there would be no more austerity.
"I was running a public service when the coalition government went down the austerity route," Mr Starmer said. "It did a huge amount of damage to our public services and we are still feeling the damage even now. So we are not going down the road of austerity."
Speaking at Downing Street on the eve of the Labour conference, the PM refused to say if he would heed union calls for a wealth tax.
But he added: "I'm acutely aware that working people have already paid a lot in extra taxes under the last government and that we need to create the conditions for our economy to grow and for investors to put their money in our economy."
CRITICAL
Mr Starmer said he had given a "raw and honest assessment" of the state of the country but he would use his speech in Liverpool to spell out how people will feel better off by the next election.
Labour's key commitments on driving up living standards, fixing the NHS, clean energy, offering opportunities to young people and tackling crime are top of his agenda.
"This would be a massively different and better country, real sunny uplands stuff," he said."
"But to get there we have to do the tough thing to start with."
The PM said the state of the NHS was one of the worst problems in his in-tray, pointing to this month's damning report by Lord Darzi which found the health service was in a "critical condition".
"It's shocking" Mr Starmer said.
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Sign In
Louie flushed
BARRY WRECKS 'EM AS HIS WONDER GOAL IS THE DIFFERENCE BETWEEN BEST OF ENEMIES
MOORE TO COME FROM MIKEY
TOTTENHAM'S huge new teenage star Mikey Moore has surprised hordes of observers over his exciting abilities.
THE TERRORISTS
Victims' horror as app lets users make digital clones of monsters
Probe after woman's body found in car boot
Discovery link to house 90 miles away
Hunt's just a quasi Kwasi
Earnings dwarfed by rival Tory clown
Three-quarters fear care crisis as they get old
Half of us have no savings for later life
JLS Oritse: I'm on cloud nine with new baby boy
Couple's elation after 2 dévastating losses
Unfit for a King.. or his tenants
30 royal rentals fail energy standards at Sandringham
LOW BLOW
Boos for Tyson & Paul in baddest fight on planet
EVERY TIPPLE HELPS
Tesco fizz wins Crimbo taste test