By Justin Parkinson
BBC News political reporter, TUC congress, Brighton
The "super-rich" should pay more tax in an effort to reduce child poverty and fight crime, says the general secretary of the Trades Union Congress (TUC).
Mr Barber said tax loopholes had to be removed
Brendan Barber said "loopholes" for UK citizens who spent time abroad meant tax breaks worth £4bn a year, putting a greater burden on lower earners.
These had to be closed, he added, with the money raised spent on reducing child poverty - a key cause of crime.
But Mr Barber denied his campaign was guided by the "politics of envy".
Speaking ahead of the TUC annual congress, which starts in Brighton on Monday, he said: "Today a significant group of super-rich float free from the rest of society, and think that tax is for the little people.
"Today the rest of society pays a heavy price for the wealth gap - whether middle, low or no income."
Mr Barber said this "distorted" the housing market, adding: "The gap harms social cohesion - and without joining the moral panic about crime rates in the UK, it's noticeable that many countries with a fairer distribution of income have lower crime rates."
Some 112,000 people currently benefit from "non-domiciliary tax breaks", he added.
When asked about the size of City bonuses, Mr Barber said they had reached £14bn in total this year.
But he added that the TUC was not calling for a change in the rate of income tax for the highest earners.
Unions, he said, had to "build support for a new progressive consensus of equality and redistribution - not based on the old politics of envy but on a new politics of cutting the costs of inequality".
Poverty costs the UK economy £40bn a year - more than £600 a person - according to the TUC.
Mr Barber said there had to be more emphasis on affordable housing and a "social wage".
He added: "The top 3% of the population own three times as much as the bottom half of the population.
"And, if you come from a poor background, you now have less chance of escaping it than you did a generation ago - an appalling legacy of the 'greed is good' 1980s."
Mr Barber promised to "encourage a debate on the values" which led to inequality.
The TUC congress runs until Thursday.