Kitchen Sink plumbing - advice please

[LIZS]

We have white plastic sink units. The plug hole seems to be secured to the pipe underneath by a central screw. The screw has broken off leaving the outlet pipe underneath loose which means water is escaping into the cupboard below. Can you just buy the new plug hole/screw or do you have to replace the short length of pipe below too ?

If the shank of the screw is still in the outlet hole then it'll be impossible to get out, best dismantle the short pipe underneath and bring to DIY shop so you get the right size, I think its watertight due to washer between the sink, washer and outlet pipe, held by the screw. Good luck

Thanks , have duck taped it together for now, fortunately can use the 1/4 sink to pour away.