Squawk 7000 for IFR (UK)

[PilotNL1983]

In the UK, when flying IFR outside of controlled airspace, and also leaving an area with radar coverage, ATC tells us we are downgraded to a basic service and often to squawk 7000 and change enroute.

Should the squawk be 7000 or 2000? I was under the impression 7000 was for VFR and 2000 for IFR.

Thanks