They're not just politicians though mate. They have their biases and are season ticket holders and traditionally enjoy "good relations" with the club's they support.
You asked me what the motives would be. I primarily gave you the motives of the club, which is obvious to me. No way shape or form will they want a rival to have a state of the art facility and tourist hub down at the docks and cutting into their profits and prestige.
Which is why the council aren't working with them on it? Oh wait...