US Military Disability Payments

Hello,
My mother is a UK citizen and my Father is a USA Citizen who want to move to the UK. Both parents are over 70 years of age. My Father currently receives monthly veteran disabilty checks.  Will he be taxed by the UK on this income, which is tax free in the USA? 
Any insight is greatly appreciated.
Thank you.

I don't know the exact answer, but I expect that the payments will fall under Article 19, Government Service. Whether the disability compensation is a pension or remuneration will dictate which paragraph of Article 19 is applicable, but both will result in zero UK tax as long as your father does not become a UK citizen.

FYI you should check into the income requirements for your mother to sponsor your father for a UK spousal visa.

Is your mother going to be able to meet the financial requirement in order to sponsor your father for a spouse visa?

Thank you for the replies.  Also, luckily, there will be no issues with the financial requirements.  My Dad meets all the partner requirements mentioned in the UK Border Agency website.