Properties granted to World War II veterans are among 150,000 hectares of farmland in northern Queensland that the Defence Department has earmarked for acquisition to allow Singaporean soldiers more room to train on Australian soil.

A group of 23 families who stand to lose their grazing properties have accused Defence of conducting a domestic "invasion" and a "land grab" on behalf of Singapore and say they will not sell.

They fear that Defence will roll over the top of them via compulsory acquisition, although so far officials have only said in letters that the properties are in an "expansion zone" and have requested face-to-face meetings with owners.

The move to expand the Army's high range training area west of Townsville is the result of a $2.2 billion deal signed in May in which the Turnbull government agreed to allow 14,000 Singaporean soldiers to train each year at Townsville and Shoalwater Bay, near Rockhampton, by 2021.