Can I get Wehlen's support for AN arbitration AND enforce a Zille referendum?

I know that Wehlen needs to be somewhat happy in the negotiations we have with them to back you for the AN arbitration regarding Aureus gas field. However I don't want to give him too much, since I am funding the ATA in Zille and I think the referendum path may be an option still.

Does the timing of the events allow me to give him just enough leverage to want to back me in the AN arbitration but not enough for him to give me back Zille? Is there a particular + value I should have in the negotiations that could trigger this?