The departure of Amber Rudd over the Windrush scandal should also mean the end of the government’s “hostile environment”, a baton the former home secretary picked up from her predecessor – and the architect of the policy – Theresa May. But this is something that is not just confined to the Home Office.

The murder of Stephen Lawrence 25 years ago, and the watershed Macpherson report that followed, brought to public attention the fact that racism does not just manifest itself as physical violence or personal abuse, but can also be institutional. William Macpherson defined it as the “collective failure of an organisation to provide an appropriate and professional service to people because of their colour, culture, or ethnic origin”.

Such failures on Windrush are stark. Commonwealth citizens – who have lived and worked in this country for decades – losing their jobs, prevented from coming home after travelling overseas, denied NHS treatment, threatened with deportation, held in detention centres or even deported. To borrow a phrase from the prime minister’s inaugural speech, these are burning injustices – black people being “treated more harshly by the criminal justice system”.

And these injustices flow directly from the government’s hostile environment policy and its decision in 2014 to remove protection for Commonwealth citizens. They are institutional. The Windrush scandal has exposed the very worst of this government.

This government may have reported on its race disparity audit but, in truth, this just brings together data we already knew – that people from diverse communities face multiple layers of disadvantage. We are still waiting for the government to act on its findings.

Wherever you look, black, Asian and minority-ethnic people are disproportionately affected by government policies, and have to jump additional hurdles to succeed. It’s the same hostile environment.

Recent reports have exposed the profoundly shocking fact that in 2016, May’s first year as prime minister, not a single one of the 339 black Caribbean applicants to the government’s civil service fast stream scheme – which identifies and trains up the next generation of senior civil servants – was successful.

NHS data shows people in the “black ethnic group” were the most likely to have been detained under the Mental Health Act in 2016-17, and people in the “white ethnic group” were the least likely. Among the specific ethnic groups, black Caribbean people had the highest rate of detention.

We know that Tory austerity has targeted diverse communities. Black and Asian households with the lowest fifth of incomes will see their living standards fall by 20%, according to the Women’s Budget Group and the Runnymede Trust, and women and ethnic minorities will be the big losers from changes to universal credit.

When Labour offered a practical solution, requiring the Treasury to carry out equality impact assessments on future budgets, the prime minister ordered her MPs to vote it down.

The introduction of fees for employment tribunals led to claims for race discrimination dropping by 58%; young black people are nine times more likely to be locked up in England and Wales than their white peers; the unemployment rate for black male graduates outstrips their white counterparts. The examples go on, infecting every area of public life. How else to describe it, other than as a hostile environment?

In opposition, Labour MPs, including Diane Abbott, Jeremy Corbyn and John McDonnell, warned about the devastating consequences this policy would have from the backbench, arguing that the immigration bill would rip lives apart, including the lives of British nationals, and that government cuts to public services would disproportionately harm diverse communities. Those same MPs are now in the shadow cabinet and leading the charge to dismantle this policy.

Sayeeda Warsi, the Tories’ most senior Muslim woman, compared this Conservative government to Enoch Powell. That ought to send a chill through Downing Street and the Home Office. Theresa May, who sent the infamous “Go Home” vans around my borough of Brent, in north-west London – an area known for its diversity – has had opportunities to take a new path but spurned them.

The Tory MP Anne Marie Morris was suspended last year for using a racist expression. But she was welcomed back to the fold earlier this year without explanation or an apology and seemingly with no punishment, putting party interest ahead of tackling racism.

And the Tories are pressing ahead with plans to demand that voters show photo ID at the ballot box, even after the Equality and Human Rights Commission said it would have a “disproportionate impact” on ethnic minority communities. This is the same hostile environment. It is extending to every part of our lives.

From the Home Office into Downing Street, racial inequality has been entrenched on Theresa May’s watch. Her new home secretary, Sajid Javid, recently said that the culture of an organisation starts at the very top. Under May, government policies have further entrenched racial inequalities. This institutional racism needs to end. It’s time she takes responsibility for the culture she created.

• Dawn Butler is the shadow minister for women and equalities