THE Premier League is facing a legal challenge that could seal Sunderland's fate - regardless of the Black Cats remarkable run of success on the pitch.

Three clubs facing relegation are preparing legal action over the League's decision not to dock Sunderland points for fielding an ineligible player earlier this season.

If it goes ahead, the move could leave Sunderland's fate in limbo during the summer as the Premier League fights a damaging court action.

According to a report in The Observer, Cardiff City, Norwich City and Fulham have already taken the first steps to initiate proceedings.

They are furious after it emerged Sunderland were given a six-figure fine - but no points deduction - for fielding an ineligible player, Ji Dong-won, in four league games earlier in the season. Ji's selection broke the rules because he needed international clearance, having being on loan to Ausburg.

Earlier this season, Ji played in four games before the mistake was spotted. Although Sunderland lost to Fulham, Crystal Palace and Manchester United, the team did scrape a draw with Southampton. 

The trio is demanding a review of the decision and, if the request is rejected, legal action could follow. They are pointing to the example of League Two side AFC Wimbledon - docked three points for the same crime.

If a review goes ahead, and Sunderland are deducted points, it could make the difference between safety and relegation.

Following an amazing sequence of results, including yesterday's 1-0 victory over Manchester United, the Black Cats sit three points above third-from-bottom Norwich.