Rugby World Cup 2015: Dylan Hartley's tournament hopes on the brink following 'headbutt' incident

Dylan Hartley sure picks his moments. This time two years ago, the England hooker talked himself out of a British and Irish Lions tour for which he had just been selected by swearing at the international referee Wayne Barnes during a Twickenham final, branding him a “cheat” into the bargain. Now, his World Cup prospects are on the line following yet another ill-timed tangle with the disciplinary class.

The Northampton captain has been cited for his part in a full and frank exchange of views between the rival packs midway through last weekend’s Premiership semi-final against Saracens at Franklin’s Gardens.

Hartley appeared to lean into his opposite number, Jamie George, and make contact with his head, and while it hardly qualified as the crime of the century – the match officials reviewed the incident immediately and saw nothing untoward – the powers that be have demanded further investigation.

Hartley must attend a tribunal in Coventry this evening and if he is found guilty, a ban will be inevitable. The minimum suspension for such an offence is four weeks and while a first-time offender might be considered eligible for a reduction, the New Zealand-born forward does not quite fall into that category, having missed 50 weeks of rugby since 2007 for a variety of deadly rugby sins, including gouging, biting, punching and elbowing, as well as that verbal abuse of a referee.

Should the verdict go against him, the very least he could expect would be expulsion from his adopted country’s two World Cup warm-up matches against France in August.

He would also be lucky to make the final preparatory game against Ireland in early September, not to mention the tournament opener with Fiji later the same month.

There is a bitter irony here, for Hartley has been eerily quiet – far too quiet, it might be argued – for much of the current campaign, which ended with Northampton’s defeat on Saturday.

He was told his fortune in no uncertain terms by the England head coach, Stuart Lancaster, before Christmas following banishment to the sin-bin for stamping at a critical juncture of the Twickenham Test match against South Africa. Since then, he has been walking, and playing, on eggshells.

Lancaster stuck with Hartley through the Six Nations and duly included him in a batch of four hookers who will prepare for the global tournament at forthcoming camps in England and the United States.

However, this latest development will not have amused the boss one little bit. He has little time for disciplinary transgressions of any kind, and having just turned his back on one key player following the Leicester centre Manu Tuilagi’s conviction on a charge of assaulting a police officer, he could have done without any further distractions.

Meanwhile, the two outstanding sides in this season’s second-tier Championship – indeed, the only clubs remotely capable of punching their weight in the top flight – meet in a promotion decider that has been on the cards since the domestic season began almost nine months ago.

Worcester, coached by the former back-row forward Dean Ryan, hold a one-point lead over Bristol, coached by the former England back-row forward Andy Robinson, after last week’s first leg in the West Country, and will start as favourites in front of a big crowd at Sixways.

Unsurprisingly, the Midlanders are fielding an unchanged line-up. Bristol, who lost the Lions Test players Gavin Henson and Ryan Jones to injury in the opening game, have made five changes, with Nicky Robinson, another high-profile Welshman, starting at outside-half.