The singer, who left the group in 2004, revealed on Twitter that he wanted to take on boybands including Take That and JLS in the charts.
"I had a dream tonight I was back on stage with westlife playing some crazy sized flootball stadium. I'm not gonna lie! I woke up smiling, (sic)" he wrote.
"If I'm to be honest yes I would love to do an album with boys and show jls and take that what we are really made of!"
He continued: "If the boys wanna challenge these newcomers I am always up for a fight. They know where. I am. Armed and ready to reclaim glory!"
McFadden criticised the chart position for the group's latest single 'Safe', after it peaked at number 10 in the UK single's chart.
"The reason I'm feeling like this is I watch my boys release an incredible emotive song and video and it play third fiddle to average... When will folk [give] them the credit they deserve.
"They are not X Factor band. They hard working creative machine who sacrificed a lot to get here."
> Westlife: 'We don't want McFadden return'