Rachael, 37, was given the boot in last night's live semi-final, finishing fourth in a public vote in the hit ITV show which has a place at the Royal Variety Performance up for grabs for the winner.
But the former Coronation Street star and West End musical singer could still make an appearance in Saturday's grand final - if the four celebrity judges vote her in on a wildcard.
Simon Cowell, Alesha Dixon, Amanda Holden and David Walliams hold Rachael's fate in their hands - as only they will have the power to decide if she returns or not.
The foursome will be able to pick any of the rejected 45 semi-finallists - while the public will also be able to send a wildcard act through to the final. However, they will only be able to choose from the acts finishing third in each of this week's live shows.
The public 'wildcard' vote will open on Thursday evening and will only be open for a short time. The two acts chosen will take to the stage in the grand final in Saturday night.
It is understood the judges will also announce their wildcard act on Thursday night.
The singer performed Gravity by Sara Bareilles - and was given a unanimous thumbs up by judges but lost out in the public vote to male crooner Wayne Woodward and stunt performer Alex Magala who were voted through with ballet duo Shannon and Peter finishing third.
The singer was 14-1 with bookmakers to win the show ahead of last night's semi final.
Donning a full-length gown, blonde-haired Rachael, who has an 11-month old daughter Emmy, was given a rapturous welcome by the audience and afterwards she told hosts Ant and Dec: "I was nervous but once I was on there I really liked it. It was a completely different level."
Rachael landed her place in the semi finals after wowing judges with a pitch perfect rendition of With You from Ghost The Musical in earlier auditions.
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