try and see, but be prepared for a long wait, i heard that it takes up to five weeks to get it, but that could be shorter now for the reasons so many are in desperate need...
UC always takes 5 weeks- not totally unreasonable as most jobs don't pay you for 4 weeks, and there is an advance payment option. The system has been overloaded but they are now ringing back if you register online.
But it's worth checking first that you are entitled- go on a benefits checker. UC takes account of household income. If his pay has fallen by 20% it might just bring you below the level for UC but may not. And savings can reduce the entitlement
I think the criteria would be:
Would you be eligible for UC if your partner were earning his full time wage?
Would you be eligible for UC if your partner earned 80% of his wage?
If you can say ‘yes’ to the last one, then you’ll probably be able to claim.