The headquarters of European Rugby Cup Ltd are in Dublin, making it perhaps fitting that Leinster have come to dominate the Heineken Cup. Victory over Ulster in Saturday’s all-Ireland final at Twickenham would be their third success in the tournament in the last four seasons following victories over Northampton last year and Leicester in 2009.

This is the 17th year of the Heineken Cup and the list of nine winners will not be added to because Ulster defeated Colomiers in the 1999 final. Whoever prevails in the west of London, Irish hands will be on the trophy for the fifth time in seven years after Munster’s successes in 2006 and 2008.

Teams have tended to have success in the Heineken Cup in clusters. Leicester’s two titles came in consecutive years from 2001, Wasps prevailed in 2004 and 2007 and Munster twice in three seasons, a feat repeated by Leinster in Cardiff three years ago.

The only consistently successful side has been Toulouse, who have won the competition a record four times and reached the final on six occasions. Ireland’s recent record in Europe has so spooked the leading French and English clubs that they are threatening to give the required notice of two years to pull out of the tournament.

They are demanding participating teams be determined on a league rather than a national basis. Under the current system, France and England each supply between six and seven clubs, Ireland and Wales three or four teams with the two professional sides in both Scotland and Italy automatically qualifying.

The French and English clubs want eight teams each to qualify from the three major leagues in Europe, the Aviva Premiership, the Top 14 and the RaboDirect Pro 12, a change that, based on this season’s table, would leave Italy unrepresented in next season’s Heineken Cup and Glasgow waving the saltire.

The Top 14 and Premiership clubs do not see why they should have to go through the rigours of a competitive qualifying process for the Heineken Cup each season, also having relegation to worry about, while the likes of Leinster and Munster can put their feet up and only field their leading players in Irish derbies.

There would also be a bigger chunk of change for the French and English grandees, but the RaboDirect nations are entitled to ask what the French, Toulouse apart, and they were distinctly average this season, bring to the Heineken Cup.

While three Irish provinces and four English clubs have won the tournament, only Brive in 1997 have succeeded from the Top 14 in addition to Toulouse. Many French teams regard qualifying for the Heineken Cup as more important than making an impact in it and focus on their 26-match league.

Yet this is the first year that both England and France have not been represented in the final and some of their teams have been distinctly underwhelming: Leicester shipped 41 points to Ulster in Ravenhill, Northampton were hit for 50 by Munster in Milton Keynes, the free-spending Racing Metro lost their three home matches and Biarritz lost to Treviso.

Ulster took an unusual route to the final, qualifying for the last eight as one of the best group runners-up having lost away to Leicester and Clermont. They won their quarter-final in Munster before subduing Edinburgh in the Dublin semi-final.

Ulster, whose success in 1999 was down, in part, to the English clubs boycotting the tournament, had for 11 years afterwards never got past the pool stage. Hard to beat at Ravenhill, they were shocking travellers but they are now fortified with South Africa steel: Johann Muller, Ruan Pienaar, Pedrie Wannenburg and Stefan Terblanche – not to forget the New Zealand prop John Afoa – have helped inject greater consistency and less excitability.

Leinster have in recent years preferred one major overseas player. Rocky Elsom was their inspiration when they won the Heineken Cup for the first time and this year Brad Thorn has made an immediate impact. At 37, the All Blacks second row will become the oldest player to appear in a final and, having won the Super 14 and World Cup, he is looking for a unique treble.

Leinster are the favourites, but they were a year ago when they trailed Northampton 22-6 at half-time before the outside-half Jonathan Sexton prompted an unlikely revival. He was at it again last month as Leinster came from behind to defeat Clermont Auvergne.

The paradox about Sexton is why he so assertive for Leinster but often dithery for Ireland. That raises the question why Ireland are struggling to replicate their provincial success at international level.

Leinster are a rounded side, competent in the set-pieces, strong at the breakdown and blessed with guile and pace behind. Ulster are not mutli-dimensional, but they are organised and strong defensively. It threatens to be tense and tight on a ground where Ireland were humbled in the Six Nations two months ago, but Sexton threatens to be the difference.