Crystal Palace football club has been called on to denounce the Democratic Football Lads Alliance (DFLA), amid concerns that the group is trying to organise among supporters at Selhurst Park.

An open letter signed by three local MPs, as well as the leader of the Croydon council, warns the DFLA has begun spreading its “message of racism, Islamophobia, anti-migrant sentiment and violence” through a Crystal Palace branch.

DFLA stickers incorporating the club’s logo have begun appearing across Croydon, including in the area around Selhurst Park stadium, activists say. On Facebook, a closed Crystal Palace DFLA group has almost 500 members.

“Stickers might be seen by some to be of little consequence but, if ignored, they are an effective way of spreading the insidious message that the far right use to sow division within our community,” the letter says. “As too are leaflets, banners, the usage of the club logo and, of course, a physical presence within and around the stadium.

“This issue has been noticed by several people within our community and was brought to one of our MPs’ attention by residents who feel threatened by the presence of the far right using the good name of Crystal Palace FC to visibly advertise within their neighbourhoods.”

Signatories include the Croydon Labour MPs Steve Reed and Sarah Jones, and Chris Philp, the Conservative MP for Croydon South. Tony Newman, the leader of Croydon council, and councillors Niroshan Sirisena and Chris Clark also signed. Crystal Palace declined to comment but said it would approach the signatories to address their concerns directly.

The letter ends with a call on the club’s directors, chief executive and manager to “issue a clear and uncompromising statement saying that the DFLA are not part of the Crystal Palace community and that they, along with their divisive views and rhetoric, are not welcome at the club we all love”.

On its website the DFLA says its goal is to “combat terrorism and extremism” and to “bring to justice anyone who believes they are above the laws of this land and the values and traditions of our country”. It says it rejects “far-left and far-right groups”.

However, antiracists pointed out that in mobilisations over the past year, DFLA members have joined demonstrations in support of Tommy Robinson, the former leader of the English Defence League, and have been addressed by Anne Marie Waters, of the anti-Islam For Britain group.

The letter, delivered to the club on Tuesday, follows a similar one to West Ham last week, after its under-18s coach and a representative of its official supporters board expressed support for the DFLA. In response, Karren Brady, West Ham’s vice-chair, defended the club’s antiracist work.