FORUM for Democracy and Development (FDD) says the decision by its former spokesperson Antonio Mwanza to join the ruling Patriotic Front (PF) is his democratic right.
Party national secretary Nathan Mulonga said the party will miss Mr Mwanza for his contribution towards the development of the party.
Mr Mulonga also said the party is scaling up its recruitment drive to attract more members.
He also said the party is united and will soon hold a convention.
But FDD member Yotam Mtayachalo said the resignation of Mr Mwanza is a wake-up call to the top leadership, adding that the party in its current form is in ‘an intensive care unit’.