Waste Connector

OK I give up !
I am in the process of replacing a bath and need to extend the existing waste connection. (The old bath had a central plughole, the new plughole is at the end of the bath). In haste I have purchased a 40mm pushfit coupler together with 40mm pipe, elbow, trap etc. On closer inspection I have found that the existing waste pipe has an external diameter closer to 45mm !
Any ideas how I can couple this to my new fittings ? I have searched Screwfix etc. in vain.

Thanks in anticipation.

It's probably a solvent weld size. But you can also use compression fittings - they fit all the sizes for eg " 1½ inch " or "40mm" pipe.

Thanks ChrisR. Just checked them out on Screwfix - exactly what I need. Easy when you know what you're looking for !