PM says Queen's Irish tour was a 'game-changer'
27 December 2011 Last updated at 08:32 GMT
The Queen's visit to Ireland earlier this year marked a new level for British-Irish relations according to the prime minister.
In an interview for Irish state broadcaster RTE, David Cameron described the Queen's four-day visit as a "game-changer" in the history of the two nations.
Mark Simpson reports.