Member States may, however, apply the aid scheme to part-time farmers who derive at least 50 % of their total income from farming, forestry, tourism, craft activities or activities for maintaining the countryside which benefit from public aid, carried out on the holding, provided that the proportion of income deriving directly from farming on the holding is not less than 25 % of the farmer's total income and that off-farm activities do not account for more than half the farmer's total working time ...