John McDonnell says it's clear whose side Boris Johnson is on: "the billionaires, the bankers and big, exploitative corporations".
The shadow chancellor said Labour believes "a new business model is needed" as he accused the prime minister of allowing the country's “super rich” to buy access to “tax breaks and corporate giveaways”.
In a speech in Westminster, he said a government led by Jeremy Corbyn would look to offer employees more of a say and make businesses a "partnership" with those involved.
"At the heart is our belief that every business should be a partnership between employees and customers, management and shareholders for the long-term success of the enterprise," said Mr McDonnell.
Mr McDonnell said a Labour government would look to introduce a 20:1 pay ratio in large companies whereby someone on the living wage of about £16,000 a year would see no one in the boardroom earning more than £350,000 a year.
Mr McDonnell said he would look to give employees a strong stake in the business they work for.
He said: "In line with our commitment to building a stakeholder economy we aim to broaden the ownership base of UK businesses to give workers more of a stake in their company.
"There is evidence to show that this not only advances long-term decision making but also boosts productivity.
"We have announced the introduction of Inclusive Ownership Funds in which larger companies will be required to transfer 1% of their shares into an employee fund until the fund owns 10% of the company.
"Shares would be owned collectively by employees with dividend payments distributed up to a maximum of £500 per employee per year."
Companies that fail to tackle climate change could be delisted from the London Stock Exchange, Mr McDonnell further warned.
Delisting occurs when a stock is removed from a stock exchange and is usually prompted by a company failing to meet the requirements of the exchange.
Companies already have to meet rules set by the London Stock Exchange and Financial Conduct Authority and Labour is proposing amending the Corporate Governance Code to put in place a minimum standard to listing relating to "evidence of necessary action being taken to tackle climate change".
Mr McDonnell said: "It will be for, basically, those companies themselves to bring forward their proposals and plans - exactly what sort of proposals they'll be, how effective they'll be.
"And then during the listing process, they'll be assessed about how successful they are either performing or how successful their plans will be.
"On that basis, just as with the rest of the code that there is, they'll then be assessed and determined if they can be listed."
The opposition party has calculated that by 2023/24, the Conservatives will have handed out “tax breaks and corporate giveaways” worth almost £100 billion since coming to power in 2010.
Labour said they included £86 billion in corporation tax cuts, £5.6 billion in reductions to inheritance tax and £5.5 billion in cuts to capital gains tax.
The Conservatives said the “top 1%” were paying a greater share of taxes than at any time under the last Labour government while tax receipts from business were at an all-time high.
Treasury Minister Simon Clarke said: “Corbyn’s Labour have revealed their true colours. They want to stop people from passing on their family homes to their children after they die.
“Rather than helping people to succeed, they want to take away your family home in higher taxes. Their plans would not hit billionaires – they would overwhelmingly hurt hard-pressed families.”
Johnson v Corbyn: The ITV Debate will be broadcast at 8pm on Tuesday 19 November, with the ITV Election Interviews broadcast at 10pm.