DERBY DAYS:There is a natural, simmering tension in every match played between these Welsh rivals, writes DAMIAN CULLEN

THIS WEEKEND rugby retreats to its core and players rediscover the primary reason why they ever went out on the field in the first place – to beat their next-door neighbour. All three countries that supply teams to the Magners League leave the Christmas period free to renew local hostilities.

At home, Connacht visit Limerick, while Ulster travel to Dublin, the fixture which three years ago set an attendance record for the competition – 48,000 spectators watching the last match at Lansdowne Road before the bulldozers moved in.

And when the musical chairs stop again next week, it’ll have Leinster in Galway and Ulster welcoming Munster – two games in which the hosts will know how much a scalp would be valued by their supporters. Priceless.

In the amateur days, before the Heineken Cup and the Celtic League were even pipe-dreams, the interprovincial title was a big crown and the interprovincial games were big encounters. Tradition keeps the supporters interested, and demands that the players respect for these clashes.

In west Wales, Scarlets will have no time to lick their wounds following the recent drubbings by Leinster when they open the Christmas round of fixtures in front of a packed Parc y Scarlets.

The Ospreys have taken to their rivalry with their opponents surprisingly quickly, considering they only came into being in 2003, with the amalgamation of two bitter adversaries, Neath RFC and Swansea RFC. And then, when the Celtic Warriors went belly up, the franchise area was extended further to Bridgend.

Believing the side may need to be reminded of whom their rivals were, a few years ago Ospreys had comedian Paul Allen write a terrace song for their supporters. The other Welsh sides didn’t see the funny side of it, which included such lyrics as:

Sometimes they comes down from the West,

In their shell suits and their vests,

They’re all dressed like Rodney Trotter,

They’re a bunch of Stradey Squatters.

The last line is a reference to the financially-strapped Llanelli-based outfit selling their stadium in the mid-1990s to the Welsh Rugby Union.

There was little need for such side-shows, as there is a natural, simmering tension in every match between the Ospreys and Scarlets, and in the corresponding fixture last year a crowd of more than 20,000 watched the Ospreys win 20-6 in a typical local derby – scrappy, with little in the way of free-flowing play, but fully committed and dominated by tough, crowd-pleasing big tackles.

And, after this weekend’s encounter with their western neighbour, the Ospreys – who include Tommy Bowe among their ranks – will turn their attention to an incursion over their eastern border.

“There is a lot riding on these derbies at this time of year,” said Cardiff Blues centre Tom Shanklin about the Christmas clashes. “You are playing against your friends and team-mates and you want to try and get one over on them. You are also playing against people who are competing for the same spots for Wales. It’s a busy time, but you want to be playing in these games because there’s a lot at stake.”

Come what may, when the new decade begins, the old animosities will be set aside and players who were pummelling each other a few short weeks earlier will be standing shoulder to shoulder in the Six Nations Championship.

Perhaps no more so than in Scotland, where almost every player in the 1872 Cup will be playing with one eye on a national shirt. The next instalment of the world’s oldest inter-city rugby match kicks off this Saturday at Firhill in Glasgow, with the return leg at Murrayfield the following weekend.

“At Edinburgh about 35 or 36 players are Scottish qualified, at Glasgow it’s about 31 or 32,” said Gordon McKie, Scottish Rugby’s chief executive. “They serve as a very useful platform for Andy Robinson to watch the talent and decide who has got the makings of being in that Scotland team when they play France in February.”

The Glasgow and Edinburgh clubs are first and second in the Magners League table and the advertisement currently running in Scotland billing the coming derby clashes reads: “For club, for country, it’s personal”.

Scarlets v Ospreys

Saturday

Scarlets v Ospreys, Parc y Scarlets, 2.05pm

Leinster v Ulster, RDS, 5.30pm, Setanta Ireland

Munster v Connacht, Limerick, 7.30pm, Setanta Ireland

Sunday

Glasgow Warriors v Edinburgh, Firhill Arena, 3.05pm

Cardiff Blues v Dragons, Cardiff City Stadium, 6pm

Dec 31st

Dragons v Scarlets, Rodney Parade, 2.05pm, Setanta Ireland

Jan 1st

Ospreys v Blues, Liberty Stadium, 5.15pm, Setanta Ireland

Jan 2nd

Edinburgh v Glasgow Warriors, Murrayfield, 3.05pm

Connacht v Leinster, Sportsground, 4pm, Setanta Ireland

Ulster v Munster Ravenhill, 6pm, Setanta Ireland