The OPP says it's legally obligated to take over policing in dozens of First Nations near the Manitoba border if the Treaty Three Police Service disbands.

The union representing Treaty Three police officers says the police service is planning to fold this summer.

If this proves to be the case, the provincial police service is preparing a contingency plan, OPP media relations officer Const. Anne McCoy said.

"This is done on a worst-case scenario basis," she said.

"The preparation of these plans does not necessarily mean the OPP expects to use them, but it is our obligation to be prepared. [We have to] make sure we have the resources … in place if it's necessary to do so."

McCoy said the OPP is still communicating with and trying to support the Treaty Three police service.

The OPP is responsible for policing all areas of the province that aren't served by municipal police forces.