Japan's negative interest rates are becoming an issue in the country's upper house election campaign, with parties debating the possibility that banks will charge retail depositors a fee for holding their savings, Bloomberg reports. Minister for Regional Revitalisation Shigeru Ishiba said negative rates would not be allowed to affect ordinary depositors. The Democratic Party, the main opposition party, has called for the Bank of Japan's negative rate policy to be overturned, arguing that it is a burden on savers and small businesses. A Florida bank, Stonegate Bank, has issued a credit card for use in Cuba, CNBC reports. Users of the card will be able to make payments at Cuban state-owned businesses and a small number of private businesses. It is the first US credit card designed for use in Cuba and will make it easier for Americans to travel and work in Cuba. The declaration of détente between the US and Cuba in 2014 allowed American card issuers to unblock debit and credit card use in Cuba. It also allowed them to establish links with Cuban banks.