After 51 years of controversy and celebration, Europe’s biggest street party – the Notting Hill carnival – opens today against one of the most politicised backdrops in its history.

Tensions surround its start following more than 650 pre-emptive arrests by police and simmering disquiet over the apparent failings of the authorities after June’s devastating fire at Grenfell Tower, where at least 80 people died. Its blackened shell stands close to the official carnival route.

Organisers yesterday appealed for the event to “lift the spirits of people” and serve as a mark of respect for the victims and those left destitute, most of whom are waiting to be rehoused. At 3pm today, and again on Monday, hundreds of thousands of revellers will observe a minute’s silence for the Grenfell dead as well as for Edson Da Costa, 25, and Rashan Charles, 20, who both died recently following contact with police. The families of both men will be attending the festival on the Love Music Hate Racism float.

Many carnivalgoers in west London are expected to wear or accessorise “green for Grenfell”. Hip-hop artist Akala was among those yesterday tweeting his support. Stafford Scott of the monitoring group, set up in the 1970s to challenge police racism, said feelings were running high among many in the black community and levels of anger were “very close” to conditions before the Broadwater farm riots in Tottenham 32 years ago. “There’s a feeling that the police are waging a war against the black community,” said Scott. Jair Tavares, Da Costa’s cousin, said the family was calling for the officers involved to be suspended and believed that recent policing tactics had stirred tensions. “It’s almost like they want something to happen so they can shut it [the carnival] down,” said Tavares. “If anything, people should be scared of going to the carnival because the police are something to be scared of. They don’t guarantee our safety.”

Scotland Yard, which is expected to have around 6,000 officers on duty, has remained unrepentant about its policing approach, which apart from 656 arrests will see facial recognition technology at the carnival, though this has been criticised by human rights group Liberty. A protective ring of steel barriers and concrete blocks and weapons checks will be in place. David Musker, the commander in charge of policing the event, said there was no specific counter-terrorism intelligence, but security plans had been “thoroughly reviewed” after the Barcelona attack on 17 August, in which 15 people died after being hit by a van.

The police have also triggered controversy after tweeting that officers had seized a kilo of heroin in Catford, south London, in a raid that it linked to the carnival, 12 miles across the capital. A statement by the Metropolitan police prompted grime star Stormzy to reply: “How many drugs did you lot seize in the run-up to Glastonbury or we only doing tweets like this for black events?” Weyman Bennett from Stand Up Against Racism said: “We need the carnival more than ever, especially as the black community is angry at the repeated deaths of their young people at the hands of the police. The carnival calls for justice and unity and we will remember Grenfell and we will hold the authorities, the government and the police to account.” Carnivalgoers will be able to offer tributes to the Grenfell victims in a quiet “reflection zone” near the blackened high-rise, where performers have been encouraged to lower their music volume in respect for those who died in the inferno. Posters have been erected at locations where the tower can be seen, asking the public not to take photographs or selfies. Medical staff will also be on hand to provide “mental health first aid” for those affected by the tragedy.

Local Labour MP Emma Dent Coad said the festival could be viewed in terms of a mass wake for the entire community. “It’s a time in the middle of the grieving to relax and honour the dead and get together and party briefly. I don’t think there’s any problem. It is a cultural thing to have a wake, and that’s how I see it,” she said.

The chair of the carnival trust, Pepe Francis, said the Grenfell tragedy had imbued the festival with even more meaning than usual. “Because of Grenfell, I would like to see the carnival this year become one of the most successful ones ever, because I think it will pay a lot of tribute to what a festival like this can do to ease the minds of the people (who are) the victims,” he said.

Francis added that he had spoken to members of the Grenfell community who had indicated they wanted the carnival to go ahead as normal. “Obviously there are varying views – some people feel it shouldn’t. But the majority feel it should, and it should be one of the best carnivals. Even the people who come and for whatever reason cause trouble – even they – I think it’s a reason for them to respect that,” he said.