Wireless promoter Live Nation has been given the green light to carry on holding the festival in Finsbury Park after a licensing review – but extra security will be on the streets and artists will be “encouraged” not to swear.

Haringey Council announced the decision at 9.15pm last night, one week after the first of two hearings at the civic centre.

The review had been brought by the Friends of Finsbury Park (FoFP) group, which had already seen its efforts to have the festival kicked out of the park rejected at the High Court.

Campaigners pointed to the anti-social behaviour the festival brings to surrounding streets that hundreds of festivalgoers pour into after the music stops. Among the complaints were drug taking and dealing, urination, vomiting and excrement on doorsteps.

The group also commissioned a sound survey at last year’s festival showing sound limits were exceeded.

It ambitiously proposed the festival capacity should be reduced from 45,000 ticketholders to 10,000.

Councillors on the licensing committee, chaired by Cllr Vincent Carroll, found some licensing objectives were undermined – public nuisance and the protection of children from harm – but decided to amend conditions on the licence rather than revoke it.

The last day of the festival will now finish half-an-hour earlier at 9.30pm, expletives will be discouraged and new sound level limits and monitoring will be in place. There will also be added security staff in streets surrounding the park.

FoFP now has 21 days to decide whether to appeal the decision. Reacting to the news, FoFP chair Simon Hunt said: “We haven’t taken any decision yet about whether to pursue this and we are just in the process of consulting our legal advisors.

“We are certainly pleased at least some of our conditions were listened to [noise and the curfew]. But several they completely disregarded which we are still concerned about such as the capacity.

“We think any event with a capacity of 50,000 people [including staff] will be disruptive and that should be recognised.”

Another FoFP member, Martin Ball, was less diplomatic. He said: “The new conditions imposed by councillors are laughable compared to what is really needed.

“New rules on the use of private security dogs and a 30 minute earlier close on the Sunday evening reveal how out-of-step Haringey’s councillors are with the public experience.”

At the hearing last week a Stroud Green’s Cllr Eldridge Culverwell asked how long the park would be “prostituted”.

Live Nation’s lawyer Philip Kolvin said Wireless was the “only festival in the world that fully represents the community in which it is based”.

“It’s a celebration of grime music,” he said. “A genre that emerged from London, from the estates, from the inner city. It’s London music – therefore, the festival celebrates the music of the people.”

The review was supported by Hackney and Islington councils and Jeremy Corbyn. Islington withdrew its submission the week before the meeting after its conditions were agreed by Live Nation.