A review is traditionally held during the week after a tournament is finished, and the only question is how quickly the IRFU want to act.

With a four-year contract in his back pocket – secured shortly before the disastrous World Cup by the IRFU – O’Sullivan is in a strong negotiating position, and his pay-off will be considerable.

Philip Browne, Chief Executive of the IRFU has said: "The IRFU shares in the disappointment with the out turn of this year's RBS Six Nations Championship from an Irish perspective and will be undertaking a detailed review of our performance.

"Our objective in this, as always, will be to ensure the Irish rugby team has in place the optimal structures to allow it to perform at the highest international levels into the future."

Talk has shifted from ’will the 49-year-old go?’ to ’when will he go?’ – and the timing of his exit hinges on the succession planning at Lansdowne Road.

Ireland’s worst championship since 1999 and lowest Six Nations finish, following hot on the heels of an abysmal World Cup and the subsequent freefall down the IRB rankings, has hammered the final nail in the coffin.

England’s easy 33-10 victory at Twickenham yesterday delivered the fatal blow, with Ireland’s collapse to an error-strewn rabble after making an explosive start – exposing the lack off confidence running throughout the team.

Even former captain Keith Wood – a staunch O’Sullivan ally – has accepted the side are regressing. But, at least in public, the man himself is determined to continue.

“Absolutely, I believe I’m the right man to lead Irish rugby,” he said.

“The big question for me is ’have I still got the hunger for the job?’ – and the answer to that is ’absolutely’.

“I love this job and have always given it 110%. If I felt I couldn’t give that then I’d be the first to admit it.

“I love this job and intend to give everything I have as long as I’m doing it.

“My position is that at this moment in time I’m not making any decisions about anything.

“What we do after every tournament is have a meeting with the Irish Rugby Football Union and discuss the bigger picture.

“After that, I suppose we’ll know what we’re doing going forward. Until then, there is not much point in doing anything.”

The IRFU have been criticised for not terminating O’Sullivan’s contract after Ireland had crashed out of the World Cup in humiliating fashion.

But justifiably the nation’s most successful Test coach was given the Six Nations to prove what had seemed destined to be his finest hour was just an aberration.

That chance has passed now. So whatever O’Sullivan – who has frequently acknowledged that he operates in a results business – says, his position has become untenable.

IRFU top brass need look only at Wales’ Grand Slam heroes to understand the enormous impact an astute and new coaching line-up can have on a gifted squad that needs nurturing to rebuild brittle confidence.

O’Sullivan is adamant he retains the support of the players – and Ronan O’Gara, the Irish captain at Twickenham, glowered when the subject turned to his boss’ future at the post-match press conference.

Whether that reflects his inner thoughts on O’Sullivan’s ability to continue in the post is unknown, but the Munster fly-half was forthcoming in supporting his coach on Friday.

Ulster centre Andrew Trimble has also backed O’Sullivan by claiming the players and not management are to blame for the malaise.

“The players are behind Eddie 100%. Everyone’s criticising Eddie, but it’s not his fault we dropped balls against England,” he said.

“We had the correct gameplan for England – but whenever it looked like we were going to score a try or come close, we knocked the ball on.

“That’s the players’ fault, and we should be taking the responsibility for what has been happening.”

Ireland made a stunning start at Twickenham, with Rob Kearney’s fourth-minute try and the kicking of O’Gara establishing a 10-0 lead inside the opening seven minutes.

But while they continued to see plenty of possession and created some reasonable chances, they blundered at key moments – while England, superbly marshalled by Danny Cipriani, were ruthless.

Confidence has clearly deserted Ireland’s players, and O’Gara admits his side’s shortcomings are currently psychological.

“There was a long break after the World Cup, and we came into the Six Nations full of optimism,” he recalled.

“We saw the win over Scotland as a new start for us, but the defeat by Wales was disappointing. Maybe we need to believe in ourselves more as players.”

O’Sullivan’s Ireland tenure may be on the brink of conclusion, but he will not be out of work for long.

His next post will surely come overseas, however.

As a shrewd operator with a wealth of experience, he still has plenty to offer - and clubs in the Guinness Premiership may be interested in his availability.

But his relationship with Ireland has run its course – and the hunt for a successor, if not already under way, will begin soon.