Lord Herman Ouseley, the chairman of football’s anti-discrimination campaign, Kick It Out, has called upon public figures, including Prime Minister, David Cameron, to moderate their language, amid signs that racism is on the rise at English football matches.

Reports of alleged racist and other discriminatory abuse made to the Football Association last season rose sharply to 887 incidents, a 21% increase on the number reported to the governing body in 2013-14.

Kick It Out also confirmed a large increase in incidents reported to it: 393 last season, a 38% rise from the 284 in 2013-14. Of those, 57%, related to racial abuse, the organisation said, while the FA also confirmed that: “Offences relating to race continue to dominate at both professional and grass roots levels.”

There were also incidents of homophobia, antisemitism and Islamophobia reported to the FA, as well as sexism and abuse aimed at disabled people.

Ouseley pointed to the Cameron’s use in July of the word “swarm” to describe people trying to come to Britain from Calais, as an example of hostile language which he said is contributing to greater prejudice.

“There is a lot of misinformation around, and the tone of the immigration discussion and austerity atmosphere, in which groups of people are depicted as being a swarm, bringing problems, coming to Britain for benefits, is feeding into people’s prejudices,” Ouseley said.

“We are seeing that reflected in football, although procedures are improving and people know they can’t get away with very much. David Cameron, and all politicians and public figures, have a duty to give leadership on how they speak about these issues, otherwise hatred will explode.”

Mark Ives, the FA’s head of judicial services, said he welcomed the increase in reports, believing it reflects a greater confidence by people to report incidents in the expectation that they would be dealt with.

“Figures for both reports and convictions [of discriminatory incidents] continue to rise,” Ives said, “as it indicates people have an increased confidence in what constitutes discrimination and how to report it. We envisaged this happening two seasons ago when we began to introduce new and clearer procedures for reporting discrimination and dealing with related cases.”

Ouseley agreed that complaints are now investigated and dealt with more quickly, and people do receive an answer.

“We are encouraged on a number of fronts,” he said.

Of the 393 total incidents reported to Kick It Out, the largest category was 165 which related to posts on social media, 80 of which were passed on to the police. Accroding to research, 134,000 offensive messages relating to football or players, appeared on social media for the period of August to March last season.