Rangers' win at St Johnstone earlier in the day had taken the Ibrox side two points clear, but Mowbray's side failed to respond as they missed a series of chances in a frustrating afternoon at Celtic Park.

The final whistle allowed the Parkhead fans to unleash a barrage of booing which had been building up throughout the game.

However, Celtic boss Mowbray was clearly agitated as he addressed the accusation of his players being negligent.

"Let's put it into perspective," he snapped.

"It is the first time we haven't scored in the league this season and we had lots and lots of chances.

"I defy anybody to say there was a lack of determination, desire or effort in the way we went about our job.

"I must congratulate Motherwell on the way they played. But I was looking at statistics, we had 24 shots on goal and 15 on target, so not scoring is the frustration.

"If we had scored two of our 15 efforts on goal we would have said 'job done, let's move on to next week.'

"Most weeks, with those stats, you would be sure that you would score one or two goals."

Mowbray continued: "I think the Celtic fans have probably booed their team off the pitch for the last 100 years if they haven't beaten Motherwell at home.

"I don't think that is anything new.

"Today we didn't win so they are entitled to let their feelings be known.

"The great thing about Celtic supporters is that generally do it at the end.

"I don't think they do get on the players' backs.

"But the supporters are within their rights to keep the standards as high as they can and I don't think the players have any qualms about that.

"It's part and parcel of playing at any big football club.

"If you play at Old Trafford, and you keep giving the ball away and missing chances, then they will let you know."

However, after criticising his central defenders in recent weeks, Mowbray turned his sights onto his players at the other end of the pitch.

"We lacked a bit of quality in the final third," he said.

"We have talked in the last few weeks about our defenders, let's talk about strikers and the midfielders who had opportunities that didn't go in.

"The defenders took a lot of flak in recent weeks and they kept a clean sheet.

"Let's hope the players who have a chance go and score a hat-full next week."

Hoops' wide-man Niall McGinn played down the impact of losing the lead at the top of the table to their Ibrox rivals.

He said: "It is disappointing but it's early enough in the season.

"It won't come down to Old Firm games, us and Rangers will drop points against other teams.

"Obviously if you don't score an early goal then the fans will get on your back and I should probably have scored with my header before the break.

"But you just have to keep plugging away.

"We are playing well enough at the moment and if we had scored in the first half it could have been two or three nil."

Motherwell boss Jim Gannon watched his side survive Celtic's late bombardment but insisted the Fir Park men deserved a point.

He said: "We did have chances to capitalise from set-pieces but the way the players equipped themselves and defended, they deserved something from the game."

Mark Reynolds claimed the Fir Park side nowadays expect to take points from the Old Firm, but admits their chances are helped when fans of Celtic and Rangers begin to turn on their own players.

"I don't think we have ever feared the Old Firm, certainly not since I've been in the side," the Motherwell defender said.

"There isn't the fear factor that was there years ago when they had bigger names.

"Any time we have played them we have went for the three points. You know if you go to Parkhead and Ibrox, and keep it at 0-0, then the longer the games goes on the more anxious the fans get.

"And when they get on to their own players, it gives you more confidence and you can start playing around them."