"Give It a Lash Jack" is a song by Liam Harrison and the Goal Celebrities. The song was made for Ireland's 1990 FIFA World Cup campaign.
It reached number one in the charts in June 1990 and stayed there for 4 weeks. It was followed up in 1994 by "Give It A Lash Again".
In a 2011 interview on RTÉ Television, film director Jim Sheridan stated that Bono and himself agreed that "Give It A Lash Jack" was the 'greatest Irish song ever written'. Check it out here http://www.youtube.com/watch?v=tXmvlJApMqg.