Isaiah (1:17) says: 'Learn to do right; seek justice. Defend the oppressed. Take up the cause of the fatherless; plead the case of the widow.' In an even more resounding phrase, Amos (5:24) says: 'But let justice roll on like a river, righteousness like a never-failing stream!'

What strikes anyone who looks at the scandalous way the Windrush generation has been treated is the rank injustice of it all.

Thousands of people from around the Commonwealth came to the UK – the 'mother country' to which they were so loyal – after the Second World War willingly to fill a labour shortage. The 1971 Immigration Act ended the free movement between Commonwealth nations that had existed until that point but gave all Commonwealth citizens living in the UK the right to remain. However the Home Office did not keep a record of those given leave to remain so they now find themselves having to prove they are here legally without having the paperwork to do so.

Now, thanks to persistent campaigning by MPs like David Lammy and exceptional journalism of reporters like Amelia Gentleman of the Guardian, we know that these people have been crushed by a conscienceless administrative machine that, instead of serving the people, served an ideology, that of a 'hostile environment' for immigrants which, in turn, was the sell-out to the hard right of politics and media.

And yes, there is racism at work here. Why else would these very British people be targeted?

As the Daily Telegraph's Juliet Samuel writes today: 'What makes the scandal so ugly is its inhumanity. People who came here as children and grew up British, who trusted their futures to this country, its government and its courts, have been cast out of the community, detained, threatened, made homeless by being unable to rent, thrown into poverty by losing their right to work and asked to pay for medical treatment despite dutifully paying taxes for decades...Perhaps some bureaucrats or ministers glanced at their pictures and assumed, without thinking, that they were troublemakers or unreliable witnesses.'

Amber Rudd was surely right to resign as home secretary after the Guardian published her January 2017 private letter to the prime minister referring to 'ambitious but deliverable' removals targets, the presence of which her recollections had been, at best sketchy. It was the accusation that she misled the House of Commons that, as so often in Westminster politics, caused her downfall.

But take a step back from the frenzy today and you see that Rudd is a typical Westminster scapegoat. She was not responsible for the policy and – as a relatively liberal, pro-EU member of the Tory government – it is surely not one she would have instigated.

It's true, too, that some Commonwealth citizens were harassed prior to the Conservatives taking office in 2010 (as I know in the case of my own Canadian mother, discussed here).

But the stark reality is that Theresa May – who once told a party conference, 'You know what they call us; the nasty party' – is responsible now. Rudd was merely her human shield.

May is the ultimate modern example of a politician seduced by the rightwing of politics and the media. As David Lammy told Rudd in the Commons recently, 'If you lie down with dogs, you get fleas.' It is the same trap in which David Cameron fell with his fateful promise of an EU referendum that has done more fiercely to divide Britain than anything since the Second World War.

May has at times posed as a Tory liberal herself. I remember her attending meetings of what in Conservative terms was the far-left Tory Reform Group around 2000. Later as home secretary, she has occasionally showed a desire to make the police – Britain's last closed shop – more accountable, and she displayed real emotion over the cause of justice for Stephen Lawrence. According to senior Tory MPs who know her, she is far from a bad person.

But perhaps it was her victory in the 2016 Tory leadership contest, when the Daily Mail led the media cheerleading for her, that went to her head. Since then, she has done all she can to keep that support, including coining the meaningless phrase 'Brexit means Brexit'. That the rightwing media need not be followed because ultimately they will back the person who stands up for what they believe in, is of course lost on her.

As Lammy recently told Christian Today: 'Theresa May feels like a politician with no conviction. She blows with the wind. She is a politician who is pragmatic to the point of weakness. Does she stand for something? And if she does then she should explain what she stands for – she should apologise or resign.

'Theresa May is not behaving like a Christian – this is not Christian, what has happened. These are not the Christian values I learned at Sunday school.'

For a true conviction prime minister, especially one locked into a wretched, endless dance over Brexit, the Windrush scandal could have provided an honourable way out. But still the vicar's daughter clings on, putting ambition first.

The thing about Isaiah and Amos is that they are inspired truth and inspirational poetry. But as the US Democrat politician Mario Cuomo said, you campaign in poetry; you govern in prose. And yes, our government has to be held accountable when its 'justice' rhetoric falls so far short of the cruel, shabby reality of what it actually does.