Conservationists, including NPA ACT, who have been campaigning to protect Bluetts Block, on Canberra's western edge, from urban sprawl have been heartened by a proposal to amend the territory's Planning Act.

An amendment proposed by the ACT Government would see parts of Bluetts Block become a nature reserve, protecting the area's significant environment values in perpetuity under the Nature Conservation Act 2014.

ACT Planning Minister Chris Steel said the government was responding to strong community support to turn the area into a nature reserve by taking the first step in consultation with the Conservator of Flora and Fauna and the ACT Parks and Conservation Service to amend the Planning Act.

The government will propose that block 403 at Stromlo and block 12 at Denman Prospect be protected, and will separately consult with the lessee of an adjacent block at Stromlo on future environmental protection.