Potentially catastrophic building safety risks, including the chance of a collapse causing a “Grenfell-scale tragedy”, are not being properly addressed by the government, a civil servant has warned in a resignation letter seen by the Guardian. The building safety minister, Lee Rowley, was reminded of the government’s safety duty after his office responded to civil servants’ calls for checks on the collapse risk of buildings by saying one option that should be considered was to “do nothing”. Leaked correspondence reveals a senior civil servant made a formal submission to Rowley last December that called on him to approve a nationwide programme to investigate crumbling concrete in schools and public buildings, and the safety of ageing social housing blocks built with the same concrete panels that caused the fatal Ronan Point collapse in 1968. But Rowley sent it back in January for a “substantial rewrite” and his private office told officials to “include the ‘do nothing’ [option]”. The internal exchange triggered the official’s resignation with a letter warning that civil servants working on policy with “potentially catastrophic life-safety implications” were not being allowed to address them “in a meaningful way”. There were “wide-ranging flaws” in the building safety system, they said. The Department for Levelling Up, Housing and Communities (DLUHC) said including the “do nothing” option was “standard practice” in policy development, and that it was untrue that civil servants were not being allowed to address building safety risks or that the system was flawed. The clash will raise fresh questions about the government’s approach to building safety since the June 2017 Grenfell Tower tragedy, in which 72 people died. The failure of previous government ministers to toughen fire regulations before the fire has already been highlighted in the public inquiry. Eight months after Rowley sent back the officials’ call for structural checks, more than 150 schools were found to have reinforced autoclaved aerated concrete (Raac) due to a separate programme of investigation led by the Department for Education, leading to last-minute classroom closures which disrupted the start of term for thousands of pupils. In the January submission, the civil servant also said the department should remind the owners of thousands of homes built from the 1960s onwards using “large panel systems” of the need for structural surveys and, potentially, strengthening works. Successive governments have failed to ensure this has been done and several blocks have recently been found to be unsafe and demolished, with residents rehoused. The civil servant resigned on 20 January, telling their seniors in the department: “It is clearly not desirable to have the responsibility [on civil servants] illustrated by the Grenfell inquiry combined with an organisational structure which does not allow for an efficient decision-making process and means of enacting change.” The submission to Rowley’s office had followed a year’s debate by an expert structural safety working group commissioned by the department. It had raised concerns about a range of risks including brick-effect cladding panels, which could fall from buildings and injure people below, and flagged that new methods of construction involving lightweight timber and steel buildings could suffer “disproportionate collapse” in fires. They resolved to ask the department to begin research into large panel system buildings and Raac, which they believed to be the most urgent concerns. Rowley’s office summarised the minister’s response by saying: “We have known about this problem for 55 years, we haven’t been able to quantify it, we’re not clear who is responsible for it and now we want to spend a year collecting data on it, but we don’t know what we’re going to do when we get it.” The email asked civil servants to produce a new submission that explained the department’s “objective” in getting involved and to set out “what meaningful options are available, including ‘do nothing’”. The civil servant responded: “The department’s objective could be seen as the avoidance of another Grenfell-scale tragedy. We will reassess the options proposed. Particularly with regard to the [large panel systems], the ‘do nothing’ [option] is not one I recommend based on the evidence we have.” Whitehall sources said the Cabinet Office had warned property leaders about safety alerts on Raac in 2021 and 2022. A spokesperson for the DLUHC said: “It is standard practice in policy development to understand the impact of a potential action compared with the status quo. Following the Grenfell Tower tragedy, the government introduced some of the toughest building safety regulations in the world through its landmark Building Safety Act. “The act also introduced a new building safety regulator to assess the safety and standards of all buildings, as well as monitor and investigate any potential risks or changes that may affect residents’ safety.”