Leilani Farha, the UN special rapporteur on the right to adequate housing, told the Guardian she was concerned that international human rights standards on housing safety may have been breached, and could have been a factor in the causes of the tragedy last June.

She was concerned that residents had told her they had been excluded from decisions about housing safety issues before the fire and had not been engaged “in a meaningful way” by the authorities about their views and needs in its aftermath.

Farha, a Canadian lawyer and the UN’s unpaid housing investigator since 2014, was in London this week on an informal visit to meet Grenfell survivors and local residents, at the invitation of human rights law academics and activists.

She said she had been struck by survivors’ “feelings of not being heard, of feeling invisible, and not being treated like equal human beings”.

“I’m concerned when I have residents saying to me they feel they are not being heard and that they are not always being treated like human beings. Those are the fundamentals of human rights: voice, dignity, and participation in solutions to their own situations.”

Safety standards in the tower – from the types of cladding used on the building to electrical circuits and ease of access to the building for fire and rescue vehicles – may have breached residents’ human rights to safe and secure housing, she said.

Although she did not meet ministers this week – a meeting with the housing secretary, Sajid Javid, could not be scheduled – Farha said she was keen to start a conversation with them and has not ruled out writing a formal letter to the UK government setting out her concerns.

The government faces increasing criticism from survivors’ groups, residents and local politicians over what they feel is an unrepresentative and overly rigid official inquiry, headed by the retired judge Sir Martin Moore-Bick.

Farha, who said her visit was not to make a formal assessment of Grenfell, said she was concerned that survivors and local residents had been stereotyped and discriminated against on the basis that they lived in social housing. This meant they may have been treated less as people with human rights, and more as objects of charity.

“Residents told me they feel the government’s position is that they should feel lucky that they are going to be rehoused and that they should feel lucky that they had social housing. That doesn’t suggest residents feel the government recognises them as rights holders.

“The fact that so many residents have said to me they are not being treated as human beings is suggestive of a society that is structured in a way where those in social housing are viewed perhaps as counting less. And that is deeply troubling.”

Farha questioned whether this may have influenced the decision to fit the tower with cheaper cladding that turned out to be flammable, reportedly to save £300,000. “If the population wasn’t viewed as somehow undeserving, as really lucky to receive the benevolence of state support for housing, if they were viewed as rights holders, I just wonder if that same decision would have been made,” she said.

Farha has been a persistent critic of what she calls the “financialisation” of housing, by which unregulated global capital is allowed to pour billions into exclusive, hyper-expensive new property developments in cities such as London, excluding local residents from local housing, pushing up rents and and fuelling housing instability.

She said it felt symbolic that Grenfell Tower was in Kensington and Chelsea, one of the wealthiest and most socially unequal boroughs in the capital: “My sense is that in London there is an emphasis on the development of property to attract money and wealth to the city. My concern is that is overemphasised, and the standards and wellbeing of tenants in social housing are underemphasised, and that is a structural issue.”

She added: “Social housing is under considerable stress in the city. I’ve heard that many council estates are scheduled for demolition for regeneration projects – which seems to mean the development of high-end properties and the displacement of those living in social housing.”

Farha said she did not want to imply the UK government had done nothing in the wake of Grenfell. It had done a great deal, she said. It was important that ministers had set up an inquiry, she said, even if it appeared to be moving slowly and was not as wide in scope as it could have been.

However, it was important the government engaged seriously and urgently with survivors and residents – who had struck her by their thoughtfulness, expertise, intelligence, and resourcefulness – and that it investigated the structural causes of the fire. “I don’t deny it is complicated, but lives are at stake. I’m hearing stories of suicidality, children being extremely traumatised. These are the days that will make or break people.”

A government spokesperson said: “Grenfell was an awful tragedy that should never have happened and nothing like it should ever be allowed to happen again. In the immediate aftermath of the fire we were clear that the council had failed the residents of Grenfell, and so we have committed to supporting everyone affected in the months and years ahead – including by rehousing residents and offering mental health support.

“Had the UN’s special rapporteur on the right to adequate housing approached the government to discuss her concerns we would gladly have met with her to discuss the work we are doing to support the Grenfell community.”

In September 2013, Farha’s predecessor as UN housing investigator, Raquel Rolnik, infuriated ministers during a formal visit to the UK when she called for the abolition of the bedroom tax on the grounds that it violated tenants’ human rights.

Rolnik warned that Britain’s relatively good record on housing rights was being eroded by the sell-off and neglect of social housing, and by welfare reforms that left poorer tenants in poverty and despair. Ministers dismissed her criticisms as a “misleading Marxist diatribe”.

Farha said she was aware some may see her as a meddling interloper. “Fair enough. On the other hand, sometimes an outside independent perspective can be really beneficial. I think this government is probably interested in some creative ideas. I would hope they would want everyone involved in Grenfell to land in a good place”.

Earlier this week, Theresa May unveiled plans to tackle what she called Britain’s “national housing crisis”. The prime minister promised a freeing up of planning rules, and pleaded with developers to “do their duty to Britain and build the homes our country needs”.

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