Yes. You can opt out at any time after being re-enrolled.
If you opt out within one month of your re-enrolment date, your employer will refund any contributions you paid while you were re-enrolled. Your re-enrolment letter will tell you the deadline for opting out.
If you miss this deadline, your employer can’t refund your contributions. They will stay in the Scheme and be invested until you retire and take your benefits, or transfer them out to another pension provider.
The re-enrolment anniversary and opt-out period are set by the government and enforced by The Pensions Regulator.