Between June 2011 and July 2013 the Launceston-based senator took 16 35-minute light plane trips, rather than make the 2 1/2-hour drive to Hobart and back.

After refusing to comment on her travel expenses last week, Senator Polley issued a statement late yesterday.

``Although I am based in Launceston many of the meetings and constituent issues I have to attend to are in Hobart or elsewhere in the state,'' Senator Polley said. 

``Therefore, in order to make myself as accessible as possible to all Tasmanians, I am sometimes required to take charter flights to do my job - this is entirely in accordance with the relevant travel entitlements.

``I take my responsibilities as a senator representing the state of Tasmania very seriously and that includes meeting constituents from across the state about the issues they're facing.''

Senator Polley is still refusing to provide details of the purpose of each trip.

Senators are allowed to spend up to $14,860 a year on chartered transport in the service of their electorate.

Senator Polley had no portfolio responsibilities at the time she made the trips.

Bass Liberal MHR Andrew Nikolic used social media to call for a better explanation. 

``All politicians have an obligation to explain why they have spent taxpayer funds,'' Mr Nikolic said on Facebook.

``Senator Helen Polley is no different.''