Under government proposals to boost infrastructure spending, pension "mega funds" will be established.

According to Treasury proposals, reforms might "unlock £80 billion" in investment, demonstrating that larger but fewer funds can yield higher returns.

Rachel Reeves, the chancellor, wants to emulate the structure of the major pension plans in Australia and Canada.

In a speech at Mansion House on Thursday night, she stated that it represents "the biggest set of reforms to the pensions market in decades" before going into further detail.

Almost 90 local government pension pots will be grouped together, with defined contribution schemes merged and assets pooled together.

This is part of the government's plan to increase economic growth through investing in infrastructure.

Pension schemes get greater returns when they reach around £20bn to £50bn as they are "better placed to invest in a wider range of assets", according to the government.

This is backed up by evidence from Canada and Australia, the government argues - with Canada's schemes investing four times more in infrastructure, and Australia three times more than the UK's defined contribution schemes.

Pensions minister Emma Reynolds told Sky News larger pension schemes are able to invest "in a more diverse range of assets, including private equity, which are higher risk, but over time give a higher return".

She said the government will not tell pension fund managers they must invest more in private equity but due to the larger scale they will be able to invest in a "broader range of assets, and that's what we see in Canada and Australia".

Ms Reynolds added that a Canadian teacher or an Australian professor is currently more likely to be invested in British infrastructure or British high-growth companies than a British saver, which she said is "wrong".

The chancellor has said the changes would "unlock tens of billions of pounds of investment in business and infrastructure, boost people's savings in retirement and drive economic growth so we can make every part of Britain better off".

However, Tom Selby, the director of public policy at financial company AJ Bell, said: "There needs to be some caution in this push to use other people's money to drive economic growth. It needs to be made very clear to members what is happening with their money."

The government says the funds will be regulated by the Financial Conduct Authority and will need to "meet rigorous standards to ensure they deliver for savers".

Local government pensions v defined contributions

The Local Government Pension Scheme in England and Wales will manage assets worth around £500bn by 2030.

These assets are currently split across 86 different administering authorities, with local government officials and councillors managing each fund.

Under the government plans, the management of local government pensions and what they invest in will be moved from councillors and local officials to "professional fund managers".

This will allow them to invest more in assets such as infrastructure, supporting economic growth and local investment on behalf of the 6.7 million public servants, the government said.

Defined contribution pension schemes are set to manage £800bn worth of assets by the end of the decade.

There are around 60 different multi-employer schemes, each investing savers' money into one or more funds. The government will consult on setting a minimum size requirement for these funds.

Businesses cautious - but pensions sector backs plans

Businesses will need to be reassured that the government's plans are watertight following the fallout from the budget, according to the trade group the Confederation of British Industry (CBI).

The CBI's chief economist Louise Hellem said: "While the chancellor is right to concentrate on mobilising investment, putting pension reform to work for the government's growth mission, unlocking investment also needs competitive and profitable businesses.

"With the budget piling additional costs on firms and squeezing their headroom to invest, the government needs to work hard to regain the confidence in the UK as a place businesses and communities can succeed.

"Pension schemes will want to operate within a UK economy that is prospering."

But key parts of the pensions sector gave their backing to the government's plans, including Standard Life, Royal London, Local Pensions Partnership Investments and the Pensions and Lifetime Savings Association.

Deputy Prime Minister Angela Rayner said: "This is about harnessing the untapped potential of the pensions belonging to millions of people, and using it as a force for good in boosting our economy."