Nearly half (49%) of employees said they deserved to be promoted within six months but 59% said they would have to switch organisations to progress their career.
The research also found that 41% of employees in local government believed they had been overlooked for promotion in the past. For 49% of these employees, the reasons for this were not explained. A further 24% said that although the reasons were explained, they did not understand them.
June Williams, director at Investors in People (UK), said: 'Bosses across local government need to be much clearer about the opportunities available and create a clear plan of action to help employees achieve their goals.'
'Without new challenges, the temptation is to seek progression by moving on elsewhere,' she added.
The findings come from YouGov interviews of more than 1,300 employees.