The Income Tax (I-T) department has issued show cause notices to around 3,500 taxpayers in the last week of March for donations made to bogus political parties in the year 2018-19. The Income Tax department can impose a penalty of up to 200 percent if the taxpayer fails to prove donations to political parties. Experts say that such taxpayers will have to pay up to 83 percent tax and penalty if they fail to prove the donation amount.