Rachel Reeves has announced plans to unlock billions of pounds from private sector pensions in her latest bid to boost economic growth.
The Chancellor will relax rules around gold-plated pensions known as defined benefit schemes - where retirement incomes are guaranteed by an employer.
These schemes - most of which are closed to new members - have been buoyed by higher interest rates in recent years, leaving an increasing number with a healthy surplus of funds.
Ms Reeves and Sir Keir Starmer will host a meeting with leaders of Britain's biggest businesses on Tuesday morning, including the bosses of Lloyds, Tesco and BAE Systems.
The pair will set out how more schemes will be able to funnel surplus pension cash back into their businesses.
The Treasury estimates that roughly three-quarters of all schemes are currently in surplus, worth £160bn.
However, experts warned that the changes were only likely to unlock a small fraction of this because of the risks involved.
Sir Steve Webb, partner at pension consultancy LCP and a former pensions minister, said that while the move was "a very welcome development", it was likely that only a limited number of schemes would take advantage of the shake-up.
He said: "In some cases, it will be possible as things stand for an employer to give a trustee enough comfort about the security of member benefits for the trustee to allow some surplus to be extracted."
However, he said that without guarantees from Britain's pensions lifeboat, known as the Pension Protection Fund (PPF) - which is ultimately guaranteed by taxpayers - extraction would be limited.
Sir Steve said: "Ideally the Government would go further and offer a way of guaranteeing member benefits, such as enhanced cover by the PPF, which would allow all surplus schemes to participate in this new option."
The Prime Minister insisted the move was part of "creative reform, the removal of hurdles, and unrelenting focus". He added: "Today's changes will unlock billions of investment, pushing forward in delivering my Plan for Change."
Ms Reeves vowed at a meeting of the Parliamentary Labour Party that she would go "further and faster" to "tear down the biggest barriers to growth", as businesses struggle following her record tax rises.
The Treasury will also seek to remove burdens on small businesses and save them millions of pounds a year by ditching plans to impose more red tape.
The Conservatives had planned to require small firms to start sharing data with HM Revenue & Customs on how many hours their employees work.