New PM briefly absorbed by case of Egypt delegate (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

( N [new] + TRUS s [reference Liz Truss, UK Prime Minister from 6th September 2022 until 25th October 2022 ] excluding the final letter S [briefly] ) contained in (absorbed by) ET ( outer letters of [case of] E gyp T )