Public inquiry proceedings cannot be adversarial, the team examining the circumstances leading up to and surrounding last year's fire at Grenfell Tower in west London has told campaigners.

Last month campaign and community groups Inquest, Grenfell United, Justice4Grenfell and Relative Justice Humanity for Grenfell wrote to the Grenfell Tower inquiry team, asking that lawyers representing bereaved families, survivors and residents be able to ask questions directly when they need to.

However in its response the inquiry team stated that a public inquiry is an inquisitorial process which calls witnesses to help get to the truth. 'Witnesses do not give evidence "for" or "against" anyone and therefore there is no place for cross-examination of the kind that takes place in court,' the letter says.

Under the Inquiry Rules 2006 legal representatives can seek permission to ask witnesses questions, otherwise this is restricted to counsel to the inquiry and the inquiry panel. Questions asked by the inquiry may include those that lawyers representing core participants have suggested based on evidence that has been disclosed to them in advance of the hearing and evidence heard during the inquiry.

The letter says: 'As you will have seen from the proceedings, legal representatives of core participants have been submitting many questions which have been put to witnesses as points have arisen. We have a clear process in place for doing this. Ensuring that questions come through a single person - one of the counsel to the inquiry - is however supportive of the witnesses, keeps the process of giving evidence straightforward, avoids duplication and ensures that the person asking the questions is aware of potential vulnerabilities. As the chairman has also explained to core participants, we need to be consistent across all witnesses in our approach to questioning.'

Responding to concerns about disclosure, the team says it has received more than 378,000 documents so far, a number that is expected to rise. The 'vast majority' of documents that have not been disclosed are relevant to issues that will be considered in 'phase two' of the inquiry.

The team says the inquiry takes its obligations under article 2 of the European Convention on Human Rights – the right to life - seriously. 'You may also be interested to note that the chairman has given his support to the suggestion that lawyers acting for the bereaved should take the lead in marshalling the evidence surrounding the circumstances in which their loved ones died,' the letter adds.