Keep Britain Tidy has given Havant Borough Council seven days to make improvements at Beachlands, Hayling Island after an inspection.
The Blue Flag status is granted to beaches under good management with excellent water quality, and hose that have education programmes on the environment.
Beachlands was among just 15 beaches in the south east to be handed a Blue Flag award.
A Havant Borough Council spokeswoman said: 'We were contacted by Keep Britain Tidy on Friday following its recent inspection of the beaches.
'Unfortunately they have reported areas of "non compliance" with the Blue Flag criteria and as a result we were asked to take down the Blue Flag. This was not because of poor water quality.
'We have been given seven days to rectify the non-compliance issues. We are taking this extremely seriously and have worked urgently on this over the weekend to ensure that we are fully compliant by the deadline or sooner if possible.
'We have asked Keep Britain Tidy to re-inspect the beaches this week and we are fully expecting to have the flag back up and flying by this weekend.'