Investigative journalist and freedom of information campaigner Heather Brooke will be the guest speaker at Monday's meeting of the Positive Action Group.
Ms Brooke was one of the main journalists who helped uncover the MPs' expenses scandal.
In an interview with the BBC, she explained what prompted her to keep chipping away at the issue (listen to audio file below):
Monday's meeting is at the Manx Legion Club in Douglas, at 7.30pm.
There is no admission charge and it's open to all.