From wiki:
In recent years, with Cardiff on the verge of a place in the Premier league, doubts have been cast on the opportunities for Welsh clubs playing in the Football League to qualify for European competitions. The FA had previously stated that they would not nominate Cardiff for a place in Europe should they earn one on the grounds that they don't have the option. However their words were contradicted by a UEFA spokesman saying that Cardiff could play in Europe as European countries are allowed to nominate teams even if they don't play within its boundaries, UEFA president Michel Platini later pledged his support to Cardiff should the FA refuse them entry to European competition, commenting: "If England don't do anything, we will."[15]
Following Platini's statement the FA announced that they would be reviewing their stance on the situation.[16] UEFA also commented on the possibility of the club being given a wild card entry into Europe,[17] but the FA eventually backed down from their previous statement and confirmed that it would allow the club to play in Europe should they win the FA Cup final.[18] However, Cardiff lost the FA Cup final 1–0 against Portsmouth, who hadn't already won a qualification place.