The key question for HMRC (who are the primary decision-makers - unless you take a test case to court when the courts decide) is whether the expenditure is 'wholly and exclusively' for business purposes. I doubt that anyone on here can give you a definitive answer to that - a tax accountant may be able to point you to previous cases where HMRC has taken a particular line.
There is more about this here.
http://www.hmrc.gov.u...relief-self-emp.htm#2
I suspect that since the sole purpose is not business-related, you are chancing your arm.
But I'd keep quiet for another reason: -
You talk about being a 'holding manager' - I trust therefore that you work for more than one organisation in this capacity? - if you work for one, that sounds like 'employed' status to me and a whole lot of other expenses that may therefore be claiming could be disallowed.
An area where I have come across something similar is teaching staff employed in the independent sector of boarding houses but not employed in the boarding houses themselves. These people do not pay anything for their accommodation at all and maintain another residence (that most rent out). Under the terms of deals done with HMRC, there is an 'assessed value' of the benefit in kind on which such people have to pay income tax. That sounds rather similar to your situation, so I am wondering whether you are already working outside of the position that HMRC would take on the matter, since you pay no tax on this. It may depend on whether you rent out your main residence.