Strictly speaking, screening is still not required (in UK) on the Excel (private or public transport) being under 10 tonnes MTOW/20 seats, but as other post says, if using a commercial airport where all airside is a restricted zone, you are going to be screened regardless, whilst the likes of Biggin, Farnborough, Cambridge, Oxford etc. don't have to if they don't want to. That's under the old post-2001 UK NASP rules.
All that said, EC300 rules which are supposed to have been implemented Europe-wide by now, require that airports do their own risk assesment and therefore will differ throughout Europe, albeit that EC300 says anything above 15 tonnes, regardless of whether it's private or public transport, has to be screened which by default implies anything under 15 tonnes doesn't.
It's still clear as mud. The UK DfT will do their own thing, the French their thing, the Swedish, their own take, and on it goes. Although there's supposed to be Europe-wide standard practice, there isn't and never will be. Accordingly, it will forever remain necessary to check policy at each individual airport in advance and indeed even between different FBOs on the same airfield.