Prosecutors to fight Baden-Clay decision all the way to the High Court.

Allison Baden-Clay’s family and friends have been given new hope that her killer husband’s murder conviction will be reinstated.

Gerard Baden-Clay’s murder conviction was downgraded to manslaughter earlier this month, a decision that angered Allison’s family and friends and led to a mass rally in Brisbane’s King George Square.

Thousands gathered for the Doing it for Allison rally on December 18, 2015.

But Queensland’s Director of Public Prosecutions looks set to lodge an appeal in the High Court of Australia that would seek to overturn the Queensland Court of Appeal decision.

The Court of Appeal ruled that it was not possible to determine beyond reasonable doubt that Gerard Baden-Clay had meant to kill his wife, and so found that his murder conviction must be overturned.

Instead, Baden-Clay remains in jail awaiting sentencing on the lesser charge of manslaughter.

His 15-years-to-life murder sentence no longer stands. The maximum penalty for manslaughter is also life imprisonment, but it is not yet known what the court will decide.

Watch Lisa Wilkinson’s passionate speech supporting Allison here:

Video via Channel 9

The Courier Mail says Queensland’s top prosecutor, Michael Byrne, QC, has been personally working on an appeal to the High Court, and that he has now informed the Queensland Government that he would be ready to file the application when the court returns from its end of year break on January 4.

Although the decision to lodge an application is a significant one, the High Court does not have to hear the case.

To have a case heard in the court you have to apply for leave to appeal. The judges then decide which cases they are going to hear. There is no further appeal option if the court decides not to hear an application.

The #doingitforAllison campaign sprung up in the wake of the Court of Appeal’s decision.

In the 2014-15 financial year the High Court heard only a small fraction of the applications that were presented. There were 428 applications for leave, but just 60 of them or 14 per cent were granted.

Still, Allison’s family and friends want to see the Court of Appeal decision challenged.

They say Baden-Clay deliberately killed his wife and deserves to be convicted of murder.

This is the next step down that long road to justice.