The Celtic League says the government is one of the weakest in living memory.
In an article to be published in the organisation's journal Carn, Bernard Moffatt says despite Tynwald members being elected on promises of renewal and transparency, it has delivered little more than drift.
In it, he calls for a directly elected Chief Minister, clear policy platforms, and full transparency in spending and performance.
And he also accused Tynwald members of looking after themselves with a backdated pay rise in 2023 while urging restraint on rises elsewhere.
Well-known farm in the west up for sale
Pet foodbank needs your help!
How much cash can government raise in 10 days, asks MHK
LegCo considers meeting on a different day
Extra promenade bus facilities would cost estimated £735k
Medieval cross returned home to Royal Chapel
Arbory MHKs in "parasite politicians" spat
Tyson Fury's boxing glove sold for £7k in charity auction