LGBT and human rights groups groups have slammed Donald Trump’s tax bill, the biggest overhaul to America’s tax system in decades, claiming it will detrimentally affect programmes and provisions in place to help marginalised communities, from access to healthcare to support for people on low incomes.

The sweeping legislation, which is expected to make around $1.5tn (£1.1tn) in tax cuts, will be voted on later on Wednesday. Republicans argue it will deliver benefits to ordinary Americans, while Democrats say it will hit the middle classes while the rich get even richer.

David Stacy, director of government affairs at the Human Rights Commission, said on Tuesday that the tax bill “threatens the healthcare of millions of Americans”.

“If the Trump-Pence tax scam becomes law, programmes crucial to the LGBTQ community like Medicare, Medicaid, global HIV and AIDS programmes, and the Ryan White Care Act will surely face future efforts to cut their benefits,” he said.

The legislation will scrap the individual insurance mandate set out in Barack Obama’s health care law, which calls for people to pay a tax penalty for not purchasing healthcare insurance.

The HRC said in a statement that repealing this provision could result in 13 million people leaving the insurance market, “causing insurance premiums to soar and leave millions priced out of access to healthcare”.

Ahead of Tuesday’s vote, Sarah Kate Ellis, president and CEO of LGBTQ media advocacy group GLAAD, said the bill would have serious consequences for America’s more marginalised communities by “directly targeting access to affordable and inclusive healthcare”.

She added: “Congressional leaders rammed through a highly unpopular and dangerous bill under the false promise of a middle-class tax cut while intentionally ignoring the devastating effects this legislation will have on LGBTQ and low-income communities.”

Thousands march against Donald Trump in LGBT rights parade Show all 8 1 /8 Thousands march against Donald Trump in LGBT rights parade Thousands march against Donald Trump in LGBT rights parade A marcher hold a sign that reads "Love is Love is Love" on the National Mall with the Washington Monument in the background during the Equality March for Unity and Pride in Washington AP Thousands march against Donald Trump in LGBT rights parade Marchers unfurl a huge rainbow flag as they prepare to march in the Equality March for Unity and Pride in Washington AP Thousands march against Donald Trump in LGBT rights parade Marchers gather to hear speakers at the end of the Los Angeles LGBTQ #ResistMarch AP Thousands march against Donald Trump in LGBT rights parade Gil Mendez, of San Francisco, holds a sign to honor the victims of the shooting at the Pulse Nightclub in Orlando as he marches during the Equality March for Unity and Pride in Washington AP Thousands march against Donald Trump in LGBT rights parade An demonstrator looks on as LGBT members and their supporters take part of the Equality March for Unity AFP/Getty Images Thousands march against Donald Trump in LGBT rights parade A marcher listens to speakers at the end of the Los Angeles LGBTQ #ResistMarch AP Thousands march against Donald Trump in LGBT rights parade LGBT members and their supporters take part of the Equality March for Unity AFP/Getty Images Thousands march against Donald Trump in LGBT rights parade A marcher mugs for the camera during the Los Angeles LGBTQ #ResistMarch AP

Newsweek reported that the individual mandate provision in the Affordable Care Act is used by people living with chronic health conditions, such as HIV/AIDS, citing census data showing that gay and bisexual men made up 67 per cent of all HIV diagnoses in 2015.

According to health policy organisation the Kaiser Family Foundation, Medicare is now the single largest source of federal financing for HIV care and treatment.

The people set to potentially lose out under the new tax bill are those who rely on the social safety net, while House speaker Paul Ryan has made comments about reforming "entitlement" programmes to tackle the current deficit.

The Associated Press reports that the budget deficit, which registered $666bn (£496bn) in the 2017 budget year, is set to soar even higher, fuelled by the tax cuts, a disaster relief total set to breach $130bn (£97bn), and long-promised, record budget increases for the military.

Trillion-dollar deficits loom before the end of Mr Trump's term, which has Republicans already planning a pivot to long-promised curbs on government benefit programmes such as food stamps, Medicaid and Medicare.

"There is no way out," Mark Sanford, Republican representative for South Carolina, said on Tuesday. "The tax bill is in essence the nail in the coffin on driving the absolute mathematical necessity of reform to entitlement programmes. You can't have both."

Mr Ryan said in an interview that "even if we get the kind of growth we hope to get (from tax cuts), you still have to reform entitlements if you're going to get this debt under control. You cannot grow your way out of the entitlement problem we have coming."

Christopher Stoll, a senior staff attorney at the National Centre for Lesbian Rights, told Newsweek earlier this month: “This bill is a disaster for everyone really, but especially for LGBT [people].

“It will result in deep cuts in programmes that LGBT people depend on,” he said, adding that LGBT people are more likely to be on middle- to low-incomes.

Members of the LGBT community “are particularly economically vulnerable” in American, according to the Williams Institute.

Research from the institute released in 2012 showed that 24 per cent of lesbians and bisexual women were considered poor, compared with 19 per cent of heterosexual women, while children of same-sex couples had poverty rates twice those of children in heterosexual married-couple households.

It also showed that transgender people are four times as likely to have a household income under $10,000 (£7,462) and were twice as likely to be unemployed.

Statistics show that 14 per cent of Americans live in poverty.

Philip Alston, the United Nations’ special rapporteur on extreme poverty and human rights told Reuters last week that the tax reform bill will create “the single most dramatic increase in inequality that could be imagined”.