The Irish claimed victory last time out at Lansdowne Road when a controversial try from Brian O'Driscoll proved decisive.
Eddie O'Sullivan's side are currently top of the RBS 6 Nations points table with two wins from two games and Laporte believes the clash could be pivotal in deciding the destiny of the title.
He said: "It's a crucial game for both sides because Ireland are still in the running for the Grand Slam.
"Ireland have really improved over the past couple of years and having won four games in a row it will be a very important game for them.
"By losing to England we pretty much lost the chance to win the championship but we have another chance to win on Saturday
"The best team won on that day. Even though we scored three tries we made too many fouls. It was a very good match in terms of intensity but we made a lot of mistakes and conceded a lot of penalties.
"As far as Saturday goes I think it is important we continue to play in the French spirit and score a maximum number of tries."