Dermot, EI7IX, noted on the ON4KST chat room that the Irish regulator, COMREG, has released new licence guidelines – the highlight of which is a new secondary allocation between 30-49 MHz.
Slovenia and South Africa already have small allocations around 40 MHz.
The multi-frequency beacon, GB3RAL, is active on 40.0050 MHz. This raises the question of some kind of allocation (probably secondary) in the UK.
One can examine the Ofcom Frequency Allocation Table (2017) to see who the existing users of this spectrum are in the UK to determine the possibilities.