Mr Nikolic, the Liberal candidate for the seat of Bass in this year's federal election, received confirmation by letter from defence parliamentary secretary David Feeney that eight full-time positions at the barracks would be cut to just one by 2015.

Mr Nikolic said the plan risked reservist training and army recruitment - claims denied by Bass Labor MHR Geoff Lyons.

Mr Nikolic said a possible reservist reduction in the state would impact overseas deployments and affect reservists' capacity to respond to emergency situations in Tasmania if called upon.

"The reduction of the reserve presence at Paterson Barracks to one-third of its current organisational structure will limit local opportunities for reserve employment," Mr Nikolic said.

"This is not just a military infrastructure issue but an important heritage issue as well."

The barracks is the home to Australia's oldest artillery unit, the 16th Field Battery.

The unit's name has been changed to the 16th Light Troop.

In the letter, Senator Feeney said there had been extensive consultation on reserve aspects of the plan. He said the plan would strengthen the defence force structure.

Mr Lyons said the transition would not put army recruitment or reserve training at risk, with reserve training to continue at the barracks. He said Paterson Barracks would not close.

Mr Lyons said in Northern Tasmania, light artillery would be withdrawn from the reserve army and replaced with mortars. "This change means that reserve members and units remain as part of the total force - allowing them to participate in and contribute capability to the army," Mr Lyons said.

"Contributing meaningful capability to the Australian Army does not put recruitment or training at risk."