Keir Starmer will make a major speech in Buckinghamshire this morning on what he calls a "plan for change" for Britain.
The prime minister will pledge to meet six explicit "milestones", including a cut to NHS waiting lists, raise living standards and build 1.5 million homes.
Another milestone is to put an additional 13,000 police officer on the streets in England and Wales.
Writing in the Sun on Sunday, the prime minister described it as "the most ambitious yet honest delivery plan in a generation".
"That means doing things a different way, and launching new, measurable milestones so the public can track our progress."
He accused the Conservatives of leaving "major problems that can’t be fixed overnight" and "there’s no point pretending otherwise".
Mr Starmer's opponents have criticised him over his speech, with the Conservatives describing it as an "emergency relaunch."
Tory leader Kemi Badenoch said he "is having to relaunch... because Labour had no plan for government".
"This is just the beginning…. there will be more resets to come.”
No 10 has denied that this is a reset, but senior government figures have raised concerns that Labour's current offering does not do enough to connect with voters.