Director's loan on ceasation

Company formed some years ago, 100 £1 ordinary shares owned. Company is now failing and will be wound up following ceasation of trade. The only creditor that will not be paid is one of the director's who has a loan account with the company. Company owes him >£300,000.

How can he obtain tax relief on this? 

Could we change the loan account into share capital and achieve a capital loss? Could this loss be eligible to be relieved against income tax?

Any suggestions much appreciated?