Mind carried out an online poll of 1,641 current and former police, fire, ambulance and search and rescue service workers.
In the south east, 70 per cent said they had contemplated suicide.
And 49 per cent said they had taken time off work due to stress, low mood or poor mental health, while 36 cent said they had experienced a mental health problem.
Mind is calling for an ‘ongoing commitment’ to the problem.
Faye McGuinness, Blue Light programme manager, said: ‘It’s shocking that our blue light workers are experiencing such high levels of mental health problems, low mood and stress.’