European football is seeing a "growing trend of polarisation" in wealth as the continent's elite clubs leave the rest behind, a new report has warned.

The annual Football Money League report - compiled by financial consultancy firm Deloitte - has shown that while the amount of revenue growth for Europe's top 20 clubs has risen from 8 per cent to 12 per cent, it is the richest teams seeing by far the biggest gains. The revenue ratio between world football's richest club and its 20th richest club has grown from 3.2:1 in 1997 to 4:1 today.

The Deloitte report notes that only 10 teams have managed to maintain their position in the Money League table (see table below) and that clubs in Europe's "big five" leagues - England, France, Germany,and commercial revenues in the last six years (148 per cent increase), compared with the €453m added by the rest of Europe’s 700 or so top-division clubs (17 per cent increase)," Uefa's Club Licensing Benchmarking Report noted.

This year three clubs - Manchester United, Real Madrid and Barcelona - posted revenues of over €600m (£520m) - the first time that feat has been achieved, while the top 20 clubs posted a total revenue of over €7.4bn.

United, which tops this year's rich list, has seen its revenue grow nearly six times in the past two decades - from £88m in 1997 to £515m last year.