Member for Shellharbour Lylea McMahon has announced her shock withdrawal from the preselection race for the seat, adding her name to a long list of Labor MPs who won't be contesting the March state election.On the eve of today's ALP preselection vote, Ms McMahon announced she would not be contesting the ballot for family reasons, reducing the field of candidates to two.She denied she was avoiding a potential loss in what was expected to be a close outcome, declaring she was confident she would have won a three-cornered contest over Wollongong nurse John Rumble and United Services Union organiser Anna Watson."I believe I would have won the preselection. I certainly was in with a good shot," Ms McMahon said."This is a difficult decision, but it's proper that I allow someone who is committed to contest the 2011 election."With preferences coming into play, the preselection ballot was always going to be a difficult one for all candidates and Ms McMahon has now thrown her support behind Ms Watson to replace her as Shellharbour MP."I'll be supporting Anna Watson," she said.Ms McMahon said it was time to put her family first.She said the decision not to recontest was one that she had been pondering for some time and her mind was made up when she attended her son Oliver’s preschool graduation on Wednesday.‘‘He was only a baby when I started ... to see him there I realised I had missed all that time ... it was very difficult,’’ she said.With her oldest son about to study for the HSC, Ms McMahon said ultimately the decision was in the best interests of her three children and husband Andrew.‘‘The preselection process really does force you to think clearly about what it is you are doing. I participated in the process ... [but] I am pulling out at this point because I am not committed to contesting the election and staying the full term.‘‘It is appropriate I give branch members the opportunity to choose between people who are.‘‘I have to put my family first and they have certainly taken a back seat for the past four years.‘‘I love this community. I’m very proud of what we’ve achieved in education and mental health, the resources that have gone into mental health are unprecedented.’’While declaring she had no regrets, Ms McMahon said she did not recommend political life for young people with families.‘‘It is a very demanding lifestyle ... I think you need to have a career and skills and experience behind you and some confidence in yourself to deal with some of the challenges you come across on a day-to-day basis. Premier Kristina Keneally said Ms McMahon had always put her community first, pushing for better services and infrastructure in Shellharbour.“Ms McMahon was a proud grassroots representative and a strong advocate for Illawarra disability organisations,’’ she said.