Sorry
You can sell the co.uk without any problems - you just need to make sure that the new owner fills out the transfer form
For a .ie sale it's not that simple ...
You can transfer ownership to someone else, but they have to be entitled to the domain. So in your case, for example, a company / business dealing in overseas property would be able to purchase the domain from you (behind closed doors as it were) and the transfer of ownership would be possible.