London - English rugby officials have been left red-faced following the leak of a pre-recorded Nike advert which hails England for winning the Six Nations Grand Slam.VIDEO: Watch the leaked England "Grand Slam" advertEngland's hopes of winning the Grand Slam were dashed on Saturday when Martin Johnson's side were routed 24-8 by Ireland in a one-sided defeat at Lansdowne Road.However a Nike advert saluting England as "Grand Slam Champions 2011" was leaked onto the Internet on Tuesday despite the team's defeat.The video shows England stars Toby Flood, Chris Ashton and Ben Foden in a series of staged action clips before signing off with the team's red rose emblem.The RFU later issued a statement expressing dismay at the leak, insisting that the footage for the advert was shot in advance for commercial reasons and denying Ireland were taken lightly."The RFU works with all its commercial partners on their sponsorship activation," the statement read."Forward planning is a crucial part of all commercial partnerships and all contingencies, winning or losing, have to be considered."It is disappointing that details of Nike's internal planning has got into the public domain."In no way did the RFU or the England team underestimate the challenge that the Ireland team would pose."We were well beaten by a team who played better and we have the utmost respect for (Ireland coach) Declan Kidney and the Irish players."