I have to re-attach a piece of plastic which is the pivot for 2 pieces
of plastic to hinge. It's like a plastic rivet. Unfortunately the top
of the 'rivet' has come off (top is about 2cm across) and needs to be
glued back onto the shaft (about 1cm diameter tube, about 2-3mm of
material).

What would be the best glue to do this, considering that it is under
quite a bit of stress when the 2 arms are flexed?

Whether or not it is a long term fix is another matter - I just need it
to work for as long as possible.

Thanks

David