Chief executive Brian Caldwell told his club website: “It’s really sad that Stuart felt that the time was right to move on.

“He had an exceptional record and has generated an impressive amount of transfer income for the club.

“He has been a critical factor in the development of Motherwell academy graduates, as well as developing young loan players during his tenure.

“When Stuart approached me, I was very disappointed to learn the effect this was having on his family and how he was feeling. No manager, player, or club employee, every one of whom gives their all for the club, should feel this way.”

Caldwell stressed that, “as a fan-owned, community-driven football club, we will always look after our own”.

The chief executive had last week pointed out that Kettlewell’s side were outperforming rivals with bigger budgets and were nine points better off at the same stage last season.

However, they lost 2-1 away to bottom side St Johnstone on Saturday and Well say Kettlewell approached Caldwell to resign on Monday morning.

“Stuart explained that some of the personal abuse was now affecting his family, to the point where they didn’t wish to attend games,” the club said.

Kettlewell, who previously managed Ross County in the top flight, has a 41.3% win percentage for his 92 games in charge, which Well point out is the highest of their seven managers since Stuart McCall left in 2014.

Well point out that he guided the side to safety from relegation in his first three months in charge, collecting 30 points out of a possible 42 as they came close to secure a top-six finish.

A 10-game unbeaten run last season was their longest since 2010 as they again narrowly missed out on the top six, while they reached the Premier Sports Cup semi-finals this season.

Assistant manager Stephen Frail will take charge of the team for Sunday’s match at home to leaders Celtic.