Several points that you might want to consider:
- Take the ownership of the task that was assigned to you by taking all of the actions that a lead should take when they lead a project. This means you need to come up with a plan of action, execute the plan, call all of the milestone meetings (make sure you use clear language in the invite to show your role and responsibility), moderate the meetings, take notes at meetings and send out minutes afterwards, build consensus and ensure things are progressing, make decision when necessary, last but not least, keep your boss posted on the progress by sending him/her a separate one-on-one email. This will let your boss see that you are in charge and you have everything under control.
- As for the competitors, try to play nice. You are absolutely right in that you don't want the boss to think that you are no team palyer. Take some shit from the competitors if you have to, don't let those trial things to make you lose the sight on what's important. Invite the competitors to your meetings, encourage them to talk and provide input. Bottomline, manage them as long as they don't overstep the boundary.
