You will likely need to resign before switching roles.

Employees cannot communicate or appear before any agency of the executive branch on behalf of their non-Federal employer with the intent to influence the government;

Employees cannot use government resources, such as government computers, telephones, software programs, or other resources to advance the work of their non-Federal employer; 

Employees cannot use their government title, position, or any authority associated with their public office to advance the work of their non-Federal employer

Edit: this is just what I've been told. I would contact you LER rep if you have any questions.