Push button bath plug is stuck - can't "unplug" th

[perssy]

I have a push button waste in the bathtub. To "plug" the bath you push the button down. Tonight it was difficult to push down, but I just pushed a bit harder. Now I cannot release the button and drain out the water. The button seems to have gone down much further than normal. Can someone tell me how to fix it?

[plumbbob]

If you place the palm of your hand on the chrome dome, you should be able to unscrew and remove the mechanism.

Once out, you should be able to see why it is jammed. Hair and other debris I would guess.