Tynwald Day organisers do not vet the private lives of guests.
The Celtic League raised the issue following the visit of Lord Sewell to last year’s ceremony.
He subsequently resigned from the House of Lords over a sex scandal.
Tynwald clerk Roger Phillips said there were 20 guests last year at a total cost of around £12,500.
He said: ‘We do not vet the private lives of our guests.
‘Inviting important visitors from off-island is a part of political engagement with opinion formers.’