Labour says it believes "in the social obligation to contribute to a fair taxation scheme for the common good".
As well as taking on "the social scourge of tax avoidance", it will lower the threshold for the 45p rate of income tax from £150,000 to £80,000 and introduce a new 50p rate on earnings over £123,000.
:: How much cash will the changes raise?
Labour has said the income tax increases will raise £6.4 billion a year. Some commentators say this is uncertain, arguing that the changes could affect earners' behaviour.
:: Who will be affected?
Labour has said the top 5% of earners will be asked to contribute more in tax, which will help to fund public services. There will be no rises in income tax for those earning below £80,000 a year.
It has said 95% of taxpayers will be guaranteed no increase in their income tax contributions, and everyone will be protected from any increase in personal national insurance contributions and VAT.
Economic think tank the Institute for Fiscal Studies (IFS) said 1.3 million people with taxable income exceeding £80,000 per year will see an impact. Currently, this "small group" pays more than 40% of all income tax, according to the IFS.
:: Could there be other impacts?
The IFS said the impact for many could be to increase their contributions to private pensions, which bring up-front income tax relief. They could also work less, make greater efforts to avoid or evade tax, emigrate, or not come to the UK in the first place, it said.
Tom Selby, a senior analyst at AJ Bell, said: "A perverse knock-on impact of this pledge is that the cost of pension tax relief provided to higher earners would rocket as under the current system it is granted at your marginal rate of income tax.
"This presumably is not the intention of the policy, and so it would be no surprise to see a Labour government take the axe to pension tax incentives."
Jason Hollands, managing director at Tilney Group, said: "Punitive taxes just deter people from working harder, especially contractors, and will negatively impact consumer spending to the detriment of the domestic economy."
:: How does the amount of tax already paid by people in the UK compare with elsewhere?
Organisation for Economic Co-operation and Development figures for 2016 suggest that top earners in countries including Sweden, France and Germany pay higher rates of income tax than they do in the UK.
:: Who is "rich"?
The IFS argued earlier this month there is a "far from perfect" overlap between people who have high incomes and people who are wealthy.
It said high-income people are those who receive a large flow of money over a period of time from salaries, bonuses, dividends or profits for the self-employed, for example.
High-wealth people are those who have built up valuable assets by a point in time, typically in property, pension pots or other financial assets.
Those who appear on the annual rich list compiled by the Sunday Times represent less than 0.00002% of the UK adult population, according to the IFS.
:: How does the housing market affect people's incomes?
Some people may have incomes considered high, but they may also have high outgoings - particularly when local incomes are compared with house prices which vary widely across the UK.
For example, a recent study by Lloyds Bank found that a home in Oxford, London, Winchester, Cambridge or Chichester, costs at least 10 times average local earnings typically. Stirling in Scotland was identified as the UK's most affordable city, with an average house price at 3.7 times local earnings.