ST LUCIA: Kevin Pietersen says he will walk off the field mid-match during the World Twenty20 and fly home if his wife goes into labour with their first child.The key England batsman must hope any volcanic explosions are limited to his time at the crease if he is to get back to London from the Caribbean in an emergency as his wife, pop star Jessica Taylor, is due on May 16 – the day of the World Twenty20 final in Barbados.”As soon as she goes into labour, I’ll be off,” Pietersen said. ”No matter where it is in the tournament, I’ll be off – and it’s been cleared with the management to do that.”If I’m in the middle of a match, I’ll obviously get off the field and then I’ll be on the next plane that flies into London Heathrow.”Pietersen, 29, rubbished critics who believe his departure would spoil the team’s campaign – they haven’t made the final of an ICC tournament in six years. ”I think it’s pretty sad that if you have your first child people criticise you for wanting to be there, whatever walk of life,” he said.England start their campaign on Monday against hosts West Indies in Guyana and will rely heavily on Pietersen, the highest-paid Indian Premier League player, who topped the run-scoring in the recent edition of the tournament.Meanwhile, Australia begin their quest to win the World Twenty20 for the first time by taking on defending champions Pakistan here (from 3.30am Monday, Sydney time) and look certain to omit specialist spinner Nathan Hauritz on a slow deck.Captain Michael Clarke said: ”Playing Pakistan, we need to have a look at how they play spin bowling, which they face a lot of. Also having David Hussey in the team, who can bowl some off-spin probably makes it harder for Haury.”Hauritz failed to take a wicket in the week’s two practice matches but, should he be left out, Australia would be the only side in the tournament not fielding a specialist spinner.Australia’s match is the second of the day at Beausejour Cricket Ground and Clarke said if the pitch had deteriorated to the point where more spin was predicted, Hauritz would come back into calculations. Otherwise, all-rounder Steve Smith would shoulder the spin burden, assisted by Clarke and Hussey.”I’ve seen how well [Hauritz has] bowled in one-day cricket, and how well he’s performed in Twenty20 cricket,” Clarke said. ”If conditions suit that extra spin option, he could definitely play a big part.”Opening batsman David Warner has already made a strong case to be favourite as the tournament’s leading run-scorer following successive half-centuries in the practice games and has been likened to Matthew Hayden.”With Davey you have to give him the freedom to play his way,” Clarke said. ”He’s got no restrictions on the way he plays. He plays a huge part, like Matty Hayden used to for us.”