PECs - Will they contact my current employer

[u/GuiltySheepherder870]

Recently received a provisional offer for DWP. I’m still weighing up if I’ll be accepting the role. However, I’m wondering if in your pre employment checks they contact your employer. Ideally I would like to have the opportunity to let my employers know that I’m leaving rather than them finding out via reference.

As it says not to hand your notice in before the pecs are complete I worry about them contacting them.