The new tax law passed by the Republican-led Congress and signed by President Donald Trump means that higher-earning Americans will pay more in income tax this year.

Personal income tax is the federal government’s largest source of revenue. In 2018, it will likely account for 50 per cent of revenue generated by Washington.

A study by the nonpartisan research group Tax Policy Center reveals that the new tax law will slash the burden for lower earners while raising the share of taxes paid by those with a household income of $150,000 or more.

In 2018, the top 20 per cent of income earners – those earning at least $150,000 a year – will pay 87 percent of income tax, according to The Wall Street Journal.

That is an increase from about 84 per cent of income tax that the top 20 per cent paid in 2017.

The new tax law passed by the Republican-led Congress and signed by President Donald Trump means that Americans in the top 1 per cent of income earners will pay more in income tax this year. The above stock image shows a 1040 income tax form

The highest earners – those making $3.2million a year – who account for the top 0.1 per cent will pay 22 per cent of all income tax in 2018.

That is an increase from 18.9 per cent in 2017.

Those in the top 1 per cent who earn at least $730,000 a year will see their share of income tax increase from 38 per cent in 2017 to 43.3 per cent this year.

The next tier of income earners – those who earn between $310,000 and $730,000 – will see a slight dip in the share of income tax.

Last year, they paid 21 per cent of the share of income tax. This year, they will pay 19.6 per cent.

Americans who earn between $217,000 and $310,000 will see no change in the share of income tax they pay this year – 11.2 per cent.

Those earning between $150,000 and $217,000 paid 13.4 per cent of income tax last year.

This year, they will pay 12.7 per cent.

By contrast, lower earning Americans will see their share of the tax burden decrease in 2018.

The lower 60 per cent of households – those who earn no more than $86,000 – will pay no net federal income tax.

Last year, this tier paid 2 per cent of income tax.

Those who earn between $48,000 and $86,000 will see their share of paid income tax drop from 5.3 per cent in 2017 to 4.3 per cent in 2018.

By contrast, lower earning Americans will see their share of the tax burden decrease in 2018. President Trump is seen second from right with Vice President Mike Pence (far right), Senator Mitch McConnell (far left), and House Speaker Paul Ryan after passage of the law in December

The bottom two tiers of income earners – those who earn up to $25,000 and those who bring in between $25,000 and $48,000 – receive benefits from the federal government through the income tax program.

That is why this tier – which makes up 77 million households - are considered to pay negative income tax.

But the study does not account for other federal taxes that lower income earners do pay – including Social Security and Medicare.

The lower tiers will also benefit from the fact that the new law almost doubled the standard deduction and expanded the tax credit for children under the age of 17.

The bottom line is that when it comes to income tax, the new tax law is more progressive than critics like to admit, according to the Journal.

In one respect, however, the study does not take into account the corporate tax cuts which will primarily benefit the wealthy.

The new tax law also doubled the estate tax exemption to $11.2million per person.

These taxes are independent of the personal income tax.

So while the new tax law will mean the richest 5 per cent of Americans will pay more in income tax, they will still benefit in other ways.