A man charged with the attempted murder of his wife after she was found near death in her car boot has vowed to challenge any move to turn off her life support system.

Joseph Korp, 47, yesterday signalled the legal battle to keep his wife, Maria Korp, 50, alive as a magistrate deferred a decision on whether to grant him bail.

If Korp was granted bail and his wife subsequently died, his charge of attempted murder could be upgraded to murder and his bail revoked because a magistrate cannot grant bail on a murder charge.

Korp and Tania Herman, 38, were charged with attempted murder, conspiracy to murder and intentionally causing serious injury after Mrs Korp was found unconscious in the boot of her car near the Shrine of Remembrance on February 13.

Mrs Korp, a mother of two, remains in a persistent vegetative state at The Alfred hospital. If she survives another month, doctors will classify her condition as a "permanent" vegetative state.

Korp's lawyer Michael Tovey, QC, said his client would oppose any move to turn Mrs Korp's life support system off. He said any ruling to make that decision would be challenged in court and could result in years of litigation and legal argument.