Stewart Regan's sudden departure from his role as Scottish FA chief executive came after a six-hour board meeting where it became clear he had lost their unanimous backing, STV understands.

Regan's immediate departure, with no notice period, was a further indication that the board did not collectively feel that he was the right man to continue in a leadership role at the home of Scottish football.

Similar roles at other organisations would be expected to have a notice period of six months or more.

Just last week, speaking to STV at the draw for the UEFA Nations League, Regan said he was not considering his position following the failure to recruit Michael O'Neill as national team manager.

The Yorkshireman said that he would continue to lead the search for Gordon Strachan's successor.

However, following the lengthy discussions at Hampden on Thursday, he resigned from his post.

In a statement released by the governing body confirming his exit, Regan reflected on what he felt were the successes of his near eight years in the job.

He said that he had "overseen a period of significant change and substantial growth" but had faced some "challenging head winds" during his time at Hampden.

Though the pursuit of O'Neill and eventual failure to recruit his number one target brought the chief executive's position into sharper focus, his tenure at Hampden has brought frequent controversy.

Regan arrived in Mount Florida from the world of Yorkshire cricket in 2010, saying that all parties could work together for the good of the Scottish game and deliver a bright future.

However, the most visible measure of the health of the national game has always been the success of the Scotland team and under Regan there was continued disappointment on the international scene.

Qualification campaigns for four tournaments ended in failure with managers Craig Levein and then Strachan both coming up short on two occasions. The timing of the departure of both was questioned by supporters and three months after Strachan was let go, the Scottish FA appear no closer to finding a successor.

The long-term health of clubs and country were addressed with plans for player development but the leadership position of performance director proved problematic during Regan's time.

Dutchman Mark Wotte appeared to deliver little progress in his three years in the role, while his successor Brian McClair left after 13 months saying he was unable to deliver "significant difference". McClair was replaced by former Cardiff City manager Malky Mackay.

Mackay's controversial part in a scandal involving racist, misogynistic and homophobic text messages meant his appointment provoked a furious response from supporters.

Regan also drew criticism for his words and actions at the time of Rangers' insolvency. The chief executive predicted "a slow and lingering death" for Scottish football if the Ibrox side was forced to play in the bottom tier. He also warned of "social unrest" if Rangers ceased to exist and was party to the "Five-way agreement" that kept details of discussions about the handling of events confidential.

Even recently, the fallout from events at Ibrox have brought Hampden and Regan into the spotlight.

Questions over the decision to allow Rangers a licence to compete in European football in 2011 have resulted in the Scottish FA compliance officer investigating the governing body's own actions.

One of the biggest issues his successor will have to address is repairing the trust between the association and football supporters, which had deteriorated during Regan's time at Hampden.