AceShowbiz - Former Westlife singer Brian McFadden has defended his decision to slam his ex-wife Kerry Katona on Twitter.com - insisting he needed to vent his anger. McFadden, who is now engaged to Delta Goodrem, has lost two legal battles to regain custody of his daughters with Katona, who he divorced in 2006 after four years of marriage.

The singer was left fuming after Katona told a U.K. tabloid he barely speaks to his girls, Molly and Lilly-Sue, and launched a bitter verbal attack on the reality TV star on the social networking site last week. He called Katona a "pig face mole", adding, "Kerry Katona ..... YOU ARE DEAD TO ME!"

McFadden now admits he wouldn't have launched the attack if he had thought about it more clearly - but he's frustrated with the ongoing custody battle. He says, "I was so infuriated when I read it and it was so typical. I just lost it and (went) straight on Twitter. You know probably the things I said, if I had've sat down and thought about it and spoke to a journalist about it, I wouldn't have said it."

"But at the end of the day I spoke from the heart. I was angry and I got my point across. I might have been a bit over-the-top, but at least I got my point across and I got to vent."

And he's hoping he will one day be able to move his daughters over to Australia, adding, "Molly's nine in August and Lilly's now seven, so there's only a few more years until they can pretty much do what they want. I would like to bring them to Australia one day and I know they want to come... I don't know (Katona) anymore and I don't know what goes through her mind."