The previous government’s decision to abandon community cohesion programmes in schools was an act of “political vandalism”, according to one of the country’s most prominent experts on race riots.

Prof Ted Cantle, who wrote a seminal report on integration after the 2001 riots, said a number of long-term measures were “abandoned” by the Conservative government, or left to “wither”.

Cantle is among a number of race relations experts to back a joint call from the leading thinktanks British Future, Belong and the Together Coalition, who are urging Keir Starmer to use this month’s Labour party conference for a “state of the nation” address that tackles the root causes of this summer’s riots and sets out how his government will rebuild community cohesion.

The organisations’ report, After the Riots, shared exclusively with the Guardian, warns that simply moving on from the violent disorder could “risk recurring episodes of the kind of disturbances we have seen, and increased polarisation and social conflict in future”.

Speaking to the Guardian, Cantle said: “With each of these riots or disturbances, we tend to deal with the immediate aftermath, rather than really digging into some of the underlying causes and trying to create a much more robust model of cohesion.

“We know what the issues are but we’ve just got to put in a long plan to deal with them. The irony is that the cost of developing cohesion is far less than the cost of the disturbances.”

He added: “There are some simple things we can do, such as reinstating the duty to promote community cohesion in schools,” and described the decision by the Conservative government to remove this from the Ofsted regime as “political vandalism”.

“It’s not just about schools. Families are involved in schools. Schools are often the centre of community activity, with spinoff associations, clubs, societies and sporting activity,” Cantle said.

The report also recommends piloting restorative justice programmes, bringing those convicted after the riots together with mosques and community organisations.

Local football and rugby league clubs should be used to increase levels of social contact across divides and develop shared local identities, the report’s authors said. The UK’s hosting of Euro 2028 in four years’ time could form the centrepiece for this work.

The calls made in the report were also backed by the former communities minister John Denham, Akeela Ahmed, who co-chaired the cross-government working group on anti-Muslim hatred, and the Rt Rev Dr Toby Howarth, the bishop of Bradford.

Cantle urged Starmer to use his speech to “develop a narrative about the way we as a society should live together. That’s going to be a little bit general, non-specific, but it can be very powerful.”

He added: “This narrative has to be supported by action about the way in which we want communities to organise, to actually bridge across divides, to build that level of trust and understanding to make sure that where there are concerns and grievances, they are dealt with.”

Sunder Katwala, a co-author of the paper and director of British Future, said: “There’s been a vacuum on communities policy for too long and this summer we saw what that can lead to. Starmer’s initial response to the riots was strong, but he shouldn’t leave the job half done. Now he needs to make clear what we will do together to stop them happening again.”

Brendan Cox, of the Together Coalition, another co-author of the paper, said: “After every riot there are a few days of panic followed by many months of reviews and then a return to business as usual. That can’t happen this time.”

Jamie Scudamore, the chief executive of Belong and a co-author of the paper, said: “We need a national strategy that empowers local leaders with the tools and resources for action, with local authorities playing a vital leadership role.”

The Ministry of Housing, Communities and Local Government has been approached for comment.