Ms. Henderson has been accused of abandoning parts of her electorate.
A message was posted on the door of her Murray Street office telling Colac constituents to contact her office in Waurn Ponds.
"Very sadly, due to the change of electoral boundaries, Colac is no longer in the Corangamite electorate.
"Accordingly, if I can provide you with any assistance, please telephone my Waurn Ponds office on 52 431 444.
"It has been an honour to represent the people of Colac.
The message has now vanished.
During his recent visit to Colac, Mr. Tehan suggested two options.
"They can either get in touch with Sarah Henderson or if they want to they can get in touch with me. I talk with Sarah on a regular basis. We've been discussing how we'll deal with various constituents' cases.