The speech was seen as laying the ground for tax rises, although it is not yet known which levies will be increased.
The Left-wing Unite union has led calls for a wealth tax, charged to the richest one per cent of the population.
The IPPR also said that wealth must be taxed more fairly, but has put forward a less drastic solution.
“In the long term, we propose a unified tax schedule for all income types, including capital gains and dividends, to align with income from work by the end of this Parliament,” the think tank said.
“In the short term, we propose the equalisation of capital gains tax with income tax implemented in the upcoming budget.”
The IPPR also demanded reform of property tax by replacing council tax with a “proportional property tax”.
This would be set at 0.48 per cent of a house’s value and would mean that the owners of more expensive homes in London and the South would pay more.
“In the long term, we support replacing the outdated and regressive council tax with a proportional property tax to reduce regional inequalities over this parliamentary term,” the think tank said.
“In the short term, we propose immediate reforms, such as higher levies on empty homes and two new additional higher council tax bands at the next fiscal event.”