Neil Lennon admits Celtic will struggle to maintain attendances and season-ticket sales unless they keep qualifying for the Champions League group stage.

SPL records show the champions have averaged 45,590 for home league games this season – down 5300 on last season's figure – and easily winning a league without Rangers has clearly proved to be a turn-off for many. An official attendance of 39,959 was given for Sunday's home match against Dundee when there seemed far fewer than that inside the stadium. Celtic could go 24 points clear at the top of the Clydesdale Bank Premier League tonight if they win at Motherwell and Inverness Caledonian Thistle lose at home to Dundee United. For Lennon, though, there was no doubt that reaching the last 16 of the Champions League had done most to maintain interest levels among supporters.

"The Champions League has driven things for everyone," he said. "It's a concern that if you don't qualify [for the group stage] then what's the season going to be like further down the line? So that's why our priority in the short-term is going to be qualification again. We have 43,000 season-ticket holders just now which, compared to a lot of other clubs, is huge. If we can get anywhere near that for next season it will be brilliant. They are not coming [to every game] but they are paying for their tickets.

"I am sure there will be a lot of people questioning if they want to renew their season tickets or not. We can't do any more than what we are doing: getting to the last 16 of the Champions League with a squad that was built with not a lot of money.

"We may be able to invest a bit heavier in the summer and, hopefully, that will attract a few more people to games."

The SPL champions must clear three rounds to reach next season's Champions League group stage but Lennon said Celtic's ability to attract quality signings, let alone fans, would depend on them achieving that.

"The hardest thing, I think, will be trying to have seasons like this one again. If we can maintain that then I don't think it's going to be an unattractive proposition for players to come here.