The banking crisis in Spain has deepened, as Moody's, the credit rating agency, has now downgraded 28 Spanish banks, including Banco Santander.

Santander suffered a ratings cut from A3 to Baa2, and that rating itself is under review for a possible further downgrade. That puts Santander one notch above Spain's government bond rating that was downgraded earlier this month to Baa3, just above junk status.

The cut to the long-term debt and deposit ratings of the banks comes just a week after the Eurozone's fourth largest economy formally sought a bailout for its banks. Moody's has stated that the reduced credit worthiness of Spanish government bonds, and the bank's links to sovereign debt, were the reason for the downgrade. The banks' ties to the real estate boom that went bust are cited as another reason.

The ratings cut of Spain's banks comes only three days after Moody's downgraded 15 of the world's biggest banks, including British banks Barclays, RBS and HSBC.

An independent audit of Spain's banks last week found that they will need up to 62bn euros in extra funding. European authorities had already agreed to provide up to 100bn euros ahead of assessments of the banks' needs.

Written and narrated by Alfred Joyner