The Winkfield lad and his bandmates have made it through to the semi-final of the hit ITV show but they are up against stiff competition to make it to the last stage.
Union J impressed judges when they sang two songs last Saturday night - The Winner Takes It All by Abba and I'll Be There by The Jackson 5.
Josh's mum, Kathryn Browne, said: "I can't quite believe they're in the semi-final."
But despite their top performance the band still found themselves in the bottom two again, battling it out against Rylan Clark but winning the judges' vote to stay in the competition with their performance of Snow Patrol's Run in the sing-off.
Kathryn said the massive backing for contestant Chris Maloney made him favourite, with James Arthur next. She believes the third place in the final will be between Union J and Jaheme Douglas - and says every vote from viewers in Bracknell will be crucial.
"I feel after Saturday that Union J deserve a place in the final; of all the contestants I think they have grown the most from when they started," said Kathryn.
"However, this won't happen without the support of Berkshire. It would be fantastic if everyone who is voting could vote a couple of extra times this weekend."
This weekend, votes count more than ever, as the result is based entirely on public opinion and there is no sing-off. Each act will sing two songs - something personal to the band and another they think will secure them a place in the last show.
Watch Union J on X Factor tomorrow (Saturday) at 8pm on ITV1. Phone lines will be open till the results show on Sunday evening.