Prime Minister Alexis Tsipras is expected to be at one rally to support the “No” vote, opposing the terms.
EU leaders have warned that a “No” vote could see Greece leave the eurozone.
Greece’s economy is already being squeezed after the country lost access to fresh funds. Banks have been shut and limits imposed on cash withdrawals.
Greece has been in deadlock with its creditors for months but only called the referendum last week.
There has been no campaigning as such, the BBC’s Chris Morris reports from Athens – just a few chaotic days as supporters and opponents of the governing Syriza party have jostled for position.
Source : BBC WORLD