Lissu, who was attacked on September 7, left the unit at a hospital in Nairobi last week, after having undergone 17 operations, CHADEMA chief Freeman Mbowe told media in Dar es Salaam.
He can now eat and sit without help and no longer requires respiratory support, Mbowe said.
When Lissu eventually leaves hospital, he will receive further treatment outside Nairobi, Mbowe added, refusing to give details for what he said were security reasons.
Lissu, 49, was shot in the stomach and leg, according to local media reports, at his home in Tanzania’s administrative capital Dodoma after returning from a parliamentary session.
According to party leaders, Lissu had previously complained of being “tailed” by a car and repeatedly said he feared assassination.
The opposition figure has had a series of run-ins with the government of President John Magufuli and had been arrested at least six times this year, accused of insulting the president and disturbing public order, among other charges.
Tanzanian police say they have opened an investigation, but Mbowe on Tuesday repeated calls for an international inquiry, describing the local force as being controlled by Magufuli’s Chama Cha Mapinduzi (CCM) party.