(p)     any amount received by or accrued to any person who is not a resident, for services rendered or work or labour done by him outside the Republic for or on behalf of any employer in the national or provincial sphere of government or any municipality in the Republic or any national or provincial public entity if not less than 80 per cent of the expenditure of such entity is defrayed directly or indirectly from funds voted by Parliament, if such amount is chargeable with income tax in the country in which he is ordinarily resident and the income tax so chargeable is borne by himself and is not paid on his behalf by the Government, the municipality concerned or such public entity;