The route is currently 46km through Laois and Kildare.
A Midlands TD says the Barrow Blueway needs its full 115km length to achieve its potential.
The route is currently 46km through Laois and Kildare, via Vicarstown.
Martin Heydon is calling for planning permission to be resubmitted for the towpath to extend through Carlow.
The stretch between Athy and Vicarstown opened recently but the junior minister says a fully developed track would be good for recreation and the local economy.