The NAO’s Windrush report shows what our reporting has pointed towards – the Home Office was long aware of the issues

One of the most concerning aspects of the report is the fact that the department has not yet established the full extent of the problems

The government’s spending watchdog has today confirmed what much of our reporting on the Windrush crisis has pointed towards – that the Home Office was well aware of the issues surrounding the scandal years before it was exposed, but ploughed on with its hostile bid to reduce immigration anyway.

In what is probably the most detailed insight yet into the departmental errors that led up to the wrongful targeting of Commonwealth immigrants, the National Audit Office (NAO) report states that the distress they suffered was “both predictable and forewarned”.

Official impact assessments by the Home Office about hostile environment measures did not give sufficient consideration to the risk of unfair consequences. In fact, ministers had been aware of “credible information” about potential issues as long as four years ago, but the warnings went ignored.

That the government had been warned about the problem isn’t really new. Looking back on the individual cases we have covered over the past eight months, many of the Commonwealth nationals affected didn’t sit quietly and accept what was happening. They did all they could to flag up their case with ministers – but to no avail.

Take Jay, the son of a Windrush immigrant who was forced to declare himself as “stateless” after he was threatened with deportation despite being born in the UK. The young man told us he had been fighting a “constant battle” to be recognised as British, spending hundreds of pounds and sending dozens of letters in failed attempts to secure his status. He showed us an entire folder of letters he had received back from MPs and ministerial offices after trying to raise his case. No one helped him in any meaningful way.

It wasn’t until The Independent published a story on Jay’s plight that the Home Office agreed to grant him a passport.

Another case is that of NHS dental assistant Donald Thompson, who went to school in Tottenham where his Windrush mother worked as an auxiliary nurse, yet had numerous applications for British citizenship repeatedly refused over 28 years. The 64-year-old said he had spent about £30,000 on Home Office legal and application fees trying to settle his case. “They have all the information they need about me. They have everything. There’s no doubt that I was here before 1973,” he told us.

And the NAO report makes clear that alongside these individual warnings were words of caution from organisations and even ministers. A 2014 report by the Legal Action Group flagged up the potential adverse impact of immigration policy on certain groups, including Jamaicans who arrived pre-1973.

Caribbean ministers raised Windrush cases with the government at a forum in April 2016, while inspection reports highlighted issues including the possibility people were being sanctioned because of incorrect data.

There was no shortage of concern raised, yet Theresa May continued to ramp up her hostile measures.

But perhaps most concerning aspect of it all is the NAO’s warning that the Home Office has not yet established the full extent of the problems. Unbelievably, there are no plans to review around 160,000 files relating to non-Caribbean Commonwealth nationals on the basis this would be “disproportionate”.

Dubbing the crisis “Windrush” – the name of the ship that brought migrants to Britain from the Caribbean in 1948 – has made it conveniently easy for ministers to pretend it is only Caribbean citizens who are affected. But migrants from other former colonies were also beckoned here decades ago, and they too are being targeted for removal.

The Home Office would be better off acting on that now rather than trying to sweep it under the carpet only for more scandals to emerge further down the line.