Church of England bishops are accusing politicians of 'dehumanising' migrants after an investigation unearthed 'shocking' levels of abuse at an immigration detention centre.

In a rare move 17 bishops plus other senior officials and different church leaders are coming together urging the government to end indefinite detention in the wake of a BBC Panorama documentary that described Brook House immigration centre as 'a toxic, brutal and failing environment where self-harming is common place'.

In a letter to the Telegraph on Wednesday the bishops say they are 'deeply concerned' by the findings and accuse 'some politicians and sectors of the media' of dehumanising immigrants.

'Yet again it raises questions about our immigration policy and practice in this country,' they write. 'We fear that this treatment is symptomatic of a rhetoric fostered by some politicians and sectors of the media that dehumanises immigrants and paints the public as "victims" of immigration.'

Signed by the Bishop of Durham Paul Butler, the third most senior figure in the CofE, as well as several other senior bishops and the chief inspector of prisons Lord Ramsbotham, the letter adds: 'As a nation we must demand better than this – both for our own citizens in whose names this takes place, and for all who find themselves in the system.'

It was organised by former G4S manager and now whistleblower and priest, Nathan Ward. It echoes his call for an absolute cap on 28 days of detention with court approval needed to hold any immigrant for longer than 72 hours.

Ward said: 'This is not about immigration; it is about ending inhumane practices which are expensive and infective. The UK is a developed nation with high standards - we must demand better than this for our detention centres.'

The criticism aimed at 'some politicians' for dehumanising migrants is similar to remarks made by the Archbishop of Canterbury last year where he accused UKIP leader Nigel Farage of racism.

Justin Welby told the home affairs select committee in the build up to the EU referendum Farage was guilty of 'inexcusable pandering to people's worries and prejudices, that is giving legitimisation to racism' and said he was 'accentuating [people's] fear for political gain and that is absolutely unacceptable'.

Home Office minister Brandon Lewis said: 'The Panorama footage is extremely disturbing and the sort of behaviour on display is utterly unacceptable. The dignity and welfare of all those in our care is of the utmost importance and we are taking this very seriously.

'It is right that G4S took swift action as soon as the allegations were brought to their attention and we will continue to work with them and the police to ensure all necessary action is taken.

'Detention and removal are essential aspects of effective immigration control and Home Office policy makes clear that detention is only used for the short period necessary. There is a presumption of liberty for all individuals.

'Home Office policy is clear that detention will only be maintained while there is a reasonable prospect of removal within a reasonable period of time.'