Attempts by Jacob Rees-Mogg to draw a line under his remarks that the victims of the Grenfell fire lacked “common sense” have drawn a furious reaction from survivors and campaigners.

The rapper Stormzy joined relatives, including the nephew of a Grenfell Tower victim who died after being told to stay put by the London fire brigade, in angrily dismissing the cabinet minister’s statement that victims should have left the burning tower block.

The leader of the House of Commons issued “a profound apology” after he told a radio interviewer: “I think if either of us were in a fire, whatever the fire brigade said, we would leave the burning building. It just seems the common sense thing to do.”

Karim Mussilhy, whose uncle Hesham Rehman, 57, died in the fire, said Rees-Mogg was an “idiot” whose remarks revealed the detachment of the government from the Grenfell community.

“The apology is too late,” he told the Guardian. “Sorry means nothing. It’s such an easy word to say. Your action means something but we have had words and no action.”

Play Video 0:58 Grenfell fire victims lacked common sense, Jacob Rees-Mogg suggests – video

The Justice 4 Grenfell group described Rees-Mogg’s original comments as “appalling” and Jeremy Corbyn called them “crass” and “insensitive”.

“What possesses someone to react to an entirely avoidable tragedy like Grenfell by saying the victims lacked common sense?” the Labour leader tweeted.

Stormzy, who has been a long-term supporter of the Grenfell survivors and spoke out against Theresa May’s response to the disaster, called on Rees-Mogg to resign, tweeting: “These politicians are actual aliens.”

“Bare [so many] of you politicians are evil and wicked and this is why we hate you,” he said. “72 people died in a tragedy that you are to blame for … This ain’t about politics, it’s about the people who govern us lacking the most basic humanity or empathy. It’s nuts to me.”

Matt Wrack, the Fire Brigades Union (FBU) general secretary, said it was “callously irresponsible” for a senior government figure to suggest the public should ignore firefighters when they are in a fire.

The outpouring of anger at Rees-Mogg’s comments came amid a difficult day for the Conservative party on the eve of their election campaign launch. Earlier, it was revealed that the Treasury would not conduct a costing of Labour’s economics plans, as the government wished, because it breached civil service impartiality rules.

Fellow Tory Andrew Bridgen later compounded the anger during an exchange with the BBC Radio 4 PM presenter, Evan Davis, in which he appeared to suggest Rees-Mogg was “cleverer” than those who died.

Play Video Jacob Rees-Mogg is cleverer than Grenfell Tower residents, says Tory MP – video

Asked whether Rees-Mogg meant to say he would have left the flats that night against official advice, Bridgen said: “That’s what he meant to say.”

Davis responded: “But in a way that is exactly what people object to, which is he is, in effect, saying: ‘I wouldn’t have died because I would have been cleverer than the people who took the fire brigade’s advice.’”

Following a long pause, Bridgen said: “But we want very clever people running the country, don’t we Evan? That’s a byproduct of what Jacob is and that’s why he is in a position of authority.”

The outrage was further intensified when it emerged that the government had placed the building firm that oversaw the disastrous refurbishment of Grenfell on an official list of companies recommended to public sector bodies seeking contractors for high-rise housing in the south of England.

That decision added “insult to injury”, according to Grenfell United, the bereaved and survivors’ group, and shocked many in the community less than a week after the chairman of the public inquiry into the disaster concluded the London fire brigade’s planning was “gravely inadequate” and that the building works broke building regulations.

“It makes me so angry,” Mussilhy said. “The detachment from the politicians in this government is still alive. This tragedy was supposed to shake and awake this nation. Two-and-a-half years on, these types of comments from a cabinet minister should not exist.

“People like my uncle couldn’t leave the tower even if they wanted to and [he] was told on several occasions firefighters were coming to get him. He took comfort in that. Did he not use his common sense?

“They are still detached. They are still clueless.”

Sir Martin Moore-Bick, who is leading the Grenfell inquiry, said more lives could have been saved if the London fire brigade dropped its “stay put” policy sooner as staff tried to tackle the blaze.

Many remained in their flats for several hours as the fire tore through the building and were trapped by heat and smoke. It emerged that 55 of the 72 people who died in the fire were told to remain in their homes.

In his apology, Rees-Mogg said: “What I meant to say is that I would have also listened to the fire brigade’s advice to stay and wait at the time. However, with what we know now and with hindsight I wouldn’t and I don’t think anyone else would.

“I would hate to upset the people of Grenfell if I was unclear in my comments. With hindsight and after reading the report, no one would follow that advice. That’s the great tragedy.”

The fire, on 14 June 2017 in the Royal Borough of Kensington and Chelsea, was the biggest single loss of life in London since the second world war.

The shadow secretary of state for housing, John Healey, said Rees-Mogg’s suggestion was shocking. “They were told to stay where they were by the fire service, who were acting on national guidelines.”

The Lib Dem candidate for Kensington and Chelsea, Sam Gyimah, said the comments were insensitive and disgraceful.

The victims of Grenfell included six members of the same family, the Choucairs, and five members of the Hashim family, who all lived on the 22nd floor. At least 18 children were killed in the disaster. Among them were a six-month-old baby, Leena Belkadi, and Logan Gomes, who was stillborn in hospital on the day.